I've been with TalkTalk now for 18 months.
First with Pipex, which started well, but went rapidly downhill.
Then with BT, which was mediocre to start with, and to end with.
I moved to TalkTalk as a financial necessity - heard LOTS of rubishing just about everywhere I looked - and must admit was holding my breath the day change-over came.

I needn't have been so pesimistic.
When the first year ended, and they wrote to me about resigning, I did so the day I got the letter.

Let's be realistic - not everything is always 100%.
I've had a couple of hiccups on the ADSL, and one one the telephone side - but these have always been promptly sorted out. On the telephone side they even redirect all land line calls to my mobile at no cost without me even having to ask.
There are a couple of times in the week when I notice a bit of congestion when the local kids are all on chatting, or catching up on their tv progs.

But I still regularly get 850kB download speeds, and even my upload speed is about 10% higher than suggested....and BT told me I could only expect a down speed approaching 4Mb/s!

I may just be lucky - but I think it is worth remembering that a lot of bad press that is put out on comparison sites is often 'suspect'in its validity.