Late reply, but hope this helps,.... I am with Orange broadband due to their offer in conjunction with mobiles (spend >£30/month - get 2MB connection free, or - as I did, pay an extra £5.00 and get upto 8MB connection).
When I joined my connnection was at aroun 7.6,... it has gradually trailed down to 2.3 and holding constant there. (ie £5.00 rip off). I live just over 1/2 mile to an upgraded exchange, but am in a semi-rural area. This is not good enough and I will look to change. There are several things you need to consider when buying broadband -
1. Contention Speed - basically, how many users/connections the provider looks to share each line with (both upspeed and downspeed is relevant), so the less users, the better
2. Once the line is in your home, how you connect - wireless is generally slower, wired is more secure and faster
3. Equipment - gernally the boxes and cables provided are base model and prone to failure/ reduce the speed, but this is not a major issue and should not really form part of the buying decision
4. Are you in a cable area? This is the most reliable and fastest speed you are going to achieve in common circumstances
There are several speed test sites,.. it is wirth trying to find the most comprensive which shows contention rates etc and thereafter tracks them. Have to say I am not overly impressed with Orange,.. but they do have cheap telephone support national/4p minute rates),.. unfortunately this seems to have been outsourced somewhere across the globe, so outside of personal feelings about jobs for domestic people this can create frustrations when dealing with poor English speakers if you are not to comfortable with IT. VNU.net is a fairly impartial site for offering speed test sites, but there are many sites around, just spend 20 mins finding which one meets your needs. As one chap said, take the BT checker with a pinch of salt, bearing in mind it is their lines that you are using!