I am but I never use it as it's part of my broadband package. In my opinion, Sky is better. TalkTalk have a nasty habit of bunging on fees for the equipment you have out of the blue. Last month, they've started charging four quid per month for their NowTV box and what's annoying is that they charge even if you don't use it. TalkTalk wouldn't be my first choice for a TV package.
A soon as I became aware of the £4 charge I disconnected the box and advised them via their chat line that I did not need this service as I never used it. They e-mailed a copy of our conversation to me so that I have something to fall back on if any charges are applied.