Yes - speed depends on the type of cable and the length of the run to the exchange. (cables don't go the straightest route to the exchange and overhead lines can give loads of problems). Think of a telephone system as a tree you can have two twigs touching but they may be on different main branches.

Just checking the link Batch as provided, there appears to be a big difference to speeds in my location. Lowest point 0.2MB for TalkTalk, 4.8MB for BT and highest point 31.3MB for Virgin.

Having had a whole heap of problems with broadband service and speeds (my lowest point at one stage was below 1MB), I now seem to have a regular 5MB from the local exchange, 1.5 miles away (approx 2.5 miles per landline). When BT OpenReach were involved with the problems, they knew there was a problem, but couldn't actually locate the precise problem, and I presume that they are still monitoring the situation. The engineer also remarked, that what you see on the surface, the line and connections below ground level, or to the boxes could be far worse, depending on age and maintenance.

You could check with the ISP, because I believe that they must now provide a realistic figure, instead of the old 'upto' way of offering and providing a service.

A mile made a big difference for me a few years ago. 6Meg a mile a way and 2Mmeg for me. Changed ISP and it went to 3Meg. Changed ISP and now near 6Meg. Had issues that connection dropped quite severely during the busy times (evenings) so they sent an Openreach broadband engineer. The 'port' in the cabinet was over congested and they've just changed me to a less congested one. It's better now as my speed only drops to about 1.7Meg (just tested) at this time. Now my ISP aren't happy about this loss of speed and have escalated this again with their suppliers (BT) and sending another BT broadband engineer next Tuesday. It's a bit unusual as this is the first time I've had an ISP that looks determined to keep my custom. Typically those that are gamers and skype users have priority over connection speed even though we might pay the same for our broadband. It's very interesting what I've learnt so far by quizzing these engineers.

This site might be interesting if you use a BT land line for connection, http://usergroup.plus.net/

Select the user tools link at the top.