Was with Talktalk for almost 4 years until April 2021. Generally a good, reliable service with good speed at a competitive price. An early problem with my line was quickly resolved with a visit from Openreach engineer.
When it was time to renew Talktalk were very reluctant to give me their current advertised price, which was stated to be available for both new and existing customers. Similar again at next renewal, hassle to get good price. I consider this to be dishonest and Talktalk simply trying to con existing customers into accepting higher price.
Final straw was them giving me notice of impending price increase on plan where they guaranteed no price increases during term of my contract. You cannot believe what they write into their contract. When I complained to Talktalk they eventually offered to reduce the price but they are dishonest and I felt unable to trust them any more.
I left Talktalk out of principle. Now with Pulse8, although about £3 per month more, it well worth it due to transparency, honesty and simplicity.