Portable connected computing is no longer synonymous only with the iPad, as a dozen Android, HP and BlackBerry tablets go onsale. In this feature we take an in-depth look at which tablet PC devices deserve your attention.

We can't argue with the success of the Apple iPad - it's given new life to a product category that had been limping along for years. The tablet PCs that used to be sold to business users were saddled with unresponsive screens and a Windows operating system (OS) that was largely unsuited to touchscreen input.

The iPad changed all that. Not only did Apple design it from the ground up to offer a finger-friendly, super-slick navigation experience, it realised that dispensing with buttons entirely was the best way to ensure there was no confusion about how you used the device - and no chance for software makers to add unnecessary navigation steps. Instead, the iPad offers simple, direct control based on touch input alone, and an OS that doesn't bog down the processor and distract from the tasks you want to achieve.

Apple introduced a new hardware design too, although it's arguably taken until the second model, launched in the UK in March, to get the desirability factor right. Let's face it, if you haven't already got an iPad, you probably want one, secretly or otherwise.

Alternatives to the iPad

But even Apple can't ignore the fact it's no longer the only tablet player in town. From a peak of nearly 95 percent market share a year ago, it now has some beefed-up competition in the form of Google Android, BlackBerry and even Windows tablets, with Microsoft having yet another stab at getting a tablet interface right.

By late June, HP will also have an alternative take on tablets on the market. The HP TouchPad, based on a revision of Palm's WebOS, will go onsale this summer.

The iPad 2 is the most high-profile tablet in town - unsurprisingly, we've included it in this round-up of the latest-and-greatest models. On its side are the breadth of the iTunes App Store, excellent web navigation and a souped-up graphics accelerator that, with the addition of the £5 iMovie app, allows you to shoot, edit and share your footage with admirable simplicity. The iPad 2 is also one of the most portable and easily the best-looking of all the tablets out there.

Apple iPad 2

But if you're not an iTunes fan and find a partly open-source option such as Android appealing, you'll want to know how it fares by comparison with Apple's all-conquering tablet. Starting with the very first tablet to run Honeycomb (version 3.0 of Google's OS, optimised for tablets), the Motorola Xoom, half a dozen big-name, high-spec Android models went onsale between late April and the end of May.

None has yet hit the heady heights of universal admiration that Apple so effortlessly achieved, but other platforms just may. Here, we look at the best tablets to buy now - and which ones to keep an eye out for in the coming months.

Motorola Xoom

Motorola Xoom

Picking your OS: Android Froyo and Honeycomb

A number of slightly cheaper tablets run version 2.2 of Google's Android OS, known as Froyo, while the big guns such as Motorola, Acer and Asus have recently begun pushing out Android 3.0 Honeycomb tablets and charging a premium for the cutting-edge technology. Some of these headline-grabbers certainly bear comparison with the iPad.

With dual-core nVidia Tegra 2 processors that run at 1GHz and can handle graphics capably, plus likeable form factors, the gap between both the original and second-gen iPad and the latest Honeycomb options is much narrower than Apple would have you believe. Onboard storage tends to be either 16GB or 32GB, with additional space for apps provided via an SD or microSD expansion card. Most accept cards up to 32GB capacity.

Almost all these Honeycomb tablets are 10.1in widescreen models - that's an awful lot of electronics to stuff into a backpack or a briefcase, however much the designers manage to shave off the weight and slim down the chassis' thickness. You also pay a pretty penny for the privilege. For a Wi-Fi model with a 10in screen you're looking at nearly £500, while a 3G version will add another £100. Even so, if you can afford 3G, get it; mobile connectivity is a real trump card for tablet PCs.

No wonder some hardware makers believe there's still mileage in Froyo when used with smaller tablets with 5 or 7in screens. It's a serviceable platform, but not optimised for tablets - in fact, Froyo was designed for Android smartphones (currently graduating towards larger screens and souped-up graphics, suggesting they may soon meet these smaller tablets somewhere in the middle).

This OS is no good for large-screen tablets, and the apps built for smartphones just play in a corner of the screen - if at all. However, with prices in the £199 to £299 range, a pocket-sized 7in Froyo tablet PC will suit many people and their budgets.

Tablet Advisor

At the pricier end of the market, it can be cheaper to buy an iPad 2 or, controversially, get a laptop instead. The Asus Eee Pad Transformer TF101 costs £429, for example. There's plenty to like about the tablet itself, but it's the same price as a decent-specification laptop. It also comes with its own docking keyboard, rather negating the point of it being a tablet. The same is true of another contender here: the Windows 7-based Acer Iconia W500. We look at this argument in more detail in 40 reasons why laptops beat tablets.

Before we go any further, let's get the Windows issue out the way. Unless you've been tasked with buying a fleet of tablets for your business and Windows is the only option on the table, we suggest you look around for something else. Windows 7 just isn't a usable option on a tablet.

Until Microsoft does what it eventually did with its lacklustre Windows Mobile OS and start over from scratch, Windows isn't the tool for the job. The interface is anything but finger-friendly, screen icons are far too small and hard to select, and the whole experience is frustrating. Even in the scenario outlined above, you'll probably end up with a job-lot of abandoned Windows tablets and staff who instead choose to use their laptops.

Next page: Size matters, security and cameras >>

Portable connected computing is no longer synonymous only with the iPad, as a dozen Android, HP and BlackBerry tablets go onsale. In this feature we take an in-depth look at which tablet PC devices deserve your attention.

Tablet buying guide: Size matters

We've had lots of discussions with makers of Windows tablets and, without exception, they've trotted out pretty lame excuses for why they are making huge widescreen tablets for business use. Security, managed services, the ability to lock down the platform and the option to add fingerprint readers for biometric control are common responses. It's simply a means of keeping down costs while 'adding value' in the form of a service contract. No one needs to take a 1kg-plus tablet with a 10in screen out and about; that screen size is merely the best-value panel size to buy.

We think the best size is somewhere between 7in and 9in - as seen in the BlackBerry PlayBook, the Dell Streak 7 and the Samsung Galaxy Tab. Each of these is also a much more portable 450g or less, making it far more likely you'll want to take them with you as a matter of course. Their screens are large enough for enjoyable web browsing, photo viewing and video playback, too.

Avoid models running processors with 600MHz or slower clock speeds if portable entertainment is on your mind; on a 10in model, expect a 1GHz CPU and a screen resolution of 1024x768 pixels. Some photos and video footage play well on a tablet, but Flash playback is unconvincing and not a reason in itself to choose one platform over another. Faced with a choice between a £500 Android tablet and a £399 iPad 2, we'd definitely choose the latter.

Dell Streak

Dell Streak

Tablet buying guide: Go about your business

Apple no longer has the clear lead in the apps market. Android has been catching up for some time - partly because the approval process is far swifter and quality control much more lax - and is set to overtake the App Store for entries imminently.

Security apps such as McAfee WaveSecure, Norton and BullGuard will help ensure you don't download a rogue app. If Dataviz DocsToGo or Mobi's Office Suite don't come preinstalled, you can get free and paid-for document editors at the Android Market. The PlayBook comes with a full version of DocsToGo since RIM owns the company that makes it. This allows both document creation and editing. The iPad, meanwhile, can natively display PDFs, Word and Excel documents, but has no built-in document editor.

Tablet Advisor

If you need full Office integration and the ability to work with Windows, a bespoke office tablet OS in the form of the HP TouchPad's WebOS looks like being far more suitable than a Windows 7 tablet. It lets you create, edit and share documents of any office stripe and has solid email credentials, including preview panes for items in your inbox, grouped conversations and so on. Android is reasonable for email as you can set up POP3, Imap and Exchange accounts, but navigating through a full inbox and sorting through contacts, calendars and task lists is not its natural territory. The iPad is good in this respect, so long as you're happy to play along with its iTunes-based import and management of your contacts.

Android users needn't avoid choosing a tablet due to limited email functionality, but power users may want to investigate a third-party app such as K9 Mail.

RIM, on the other hand, has email so tightly parcelled up between its smartphones and its tablet we were initially concerned that we wouldn't be able to use the PlayBook without a BlackBerry phone. Secure messaging via BBM and the BlackBerry Email server are supported, but you can also log into webmail and other Imap clients without needing your smartphone to hand.

Tablet buying guide

Tablet buying guide: When cameras go crazy

Apple introduced FaceTime video chat with the iPad 2, but it's not the only tablet to have dual cameras. The Honeycomb tablets we reviewed in our group test each sport at least a 1.3Mp webcam and a 3Mp main camera, with flash, VGA video recording and a digital zoom.

You can video conference with a tablet, but even the 2Mp webcams on the Motorola Xoom and the Asus Eee Pad are no great shakes. You really need something to hold the tablet steady too. Photo viewing, on the other hand, is a great experience on many of these tablets, with smooth scrolling, pinch-to-zoom and audio soundtracks for your slideshows.

For more information on choosing a tablet PC, take a look at our guide, Which tablet PC is best for you?