I have heard great and wonderful things about Firefox, but when I gave it a try the other day, I was greatly disappointed.
The user interface was drab and boring. It looked much more like Win9x rather than XP.
The tabbed browsing, offers no more flexibility than the Windows taskbar. The po-up blocker let 5 pop-ups though, that the google toolbar normally blocks. It asked me the same dumb questions about downloading files, that SP2 does. It made me download the full Macromedia Flash player to view flash movies, and trying to use it to access my pop3 emails seemed like a nightmare.
As for the hackers... People only hack IE and Windows, because they are the most used products. If everyone started using Firefox tomorrow, Firefox would be hacked till it was turned into a cripple. Firefox is only going to be a secure internet browser as long as a very small minority use it. The same applies to Linux. Anyway, the few problems IE has, are easily solved with a good anti-virus, firewall and Spybot: Search and Destroy. ;)
It may be a good idea for sceurity freaks, who worry about every single hole there is in their computer, but there becomes a point when you have to sacrifice the odd hole, to be able to view a webpage in its full glory.
As a website creator, I know how much incredible hard work goes in, and to see it viewed through another browser, where they haven't put in the effort to make it fully compatible with the worldwide web, and half your webpage doesn't work, is quite upsetting.
You spend hours making a webpage, and then some guy comes along with an incompatible browser, and the "very well made wesite" is turned into a "the author doesn't bother to make sure the website works properly" website.
If companies want to make successful browsers, which will make people swarm to use them, then they must make their browser compatible with the www. The authors of the www (being web developers) are never going to take out all the bits one browser doesn't like.
It just seems incredibly stupid to me, to have a browser that doesn't show webpages correctly.
It also seems stupid that people think that Firefox is 100% safe, while in-fact, we don't know. Until it becomes popular enough for hackers to want to hack it, there is no telling how many or how fewer holes there are in it. However I will agree, at the moment, that Firefox is a safer browser... if you can put up with some parts of webpages failing to work.