I have 4 friends who recently swapped over to Talk Talk - spread across Liverpool. The general consensus is not good. Their CS leaves a lot to be desired and if you can actually get both your phone line and broadband working together - you're one of a lucky few.
One of my friends has tried to get out of the contract and has taken advice from CAB, OFCOM/OFTEL (not sure which) and has been advised to go down the official route of complaining and trying to get her issues sorted, otherwise talk talk can demand a 'get out' fee. There is a website dedicated to Talk Talk problems
http://talktalkhell.wordpress.com/ if you'd like to read up about it yourself.
I'm sorry its not very positive, but i'm sure their experience has saved me a whole lot of stress. Try virgin adsl, i can't really fault it so far. I get evening and weekend landline calls for free and 'up to' 8 meg for £14.99 in addition to BT line rental (£11 i think). For the sake of a fiver and your sanity, i know what i'd do.