I used to be a big fan of BT Openworld. I had BT since ISDN was available through Home Highway. When their ADSL packages came out I upgraded to that to. Speeds were great. Then ADSL+ packages were released and I opted for Option 4, which offered a then up to 8Mbps (usually 5-6Mbps all day) service with a 30GB bandwidth cap at £29.99 a month.
Recently BT has become a total nightmare. Because I didn't want to upgrade to a new 18 month contract BT Total Broadband, taking all of their other unnecessary services such as a Home Hub and Phone with their new Option 3 package which has an up to 8Mbps package with an unlimited bandwidth for £24.99. Because I accidentally went over my 30GB bandwidth allowance I was limited to 512Kbps download limit at peak times (I assume 6pm to 12am) for more than two months. Even know I was paying through the nose above their Option 3 package.
I finally had enough, I quit BT after 6 years on ADSL and when I called to obtain my MAC code, they tried to hard sell me with their new option 3 package and 18 month contract. Telling me that the bandwidth cap would be lifted if I agreed there and then.
Avoid like the plague.
I have moved to Aquiss, I am on a business package, and I am extremely happy with the service. They have a £32.99 package which includes up to 8Mbps download & 832Kbps upload (I am averaging 6Mbps/650Kbps respectively 24/7). More than enough bandwidth allowance at 45GB at peak times and 300GB at off-peak times. A 1 month contract and you can upgrade or downgrade your account with 10 days notice. Support is great. They answer your questions quickly and DON'T put you through to a foreign country. They did have a few outage problems when I first arrived, but these were explained in detail on their support website and the problems didnt last for more than a couple of hours. For the past month and a half I have not had any downtime at all. Highly recommended.