We had FTTPoD installed by Cerberus who were brilliant but expensive, and stuck with them for 4 years. We switched to FTTP from PlusNet and we are just coming up to 2 years since transferring over to them. We dropped a tier, from 900 to 500mbps, but even so, the responsiveness of the service can be a bit hit and miss at times. I assume my traffic is going via PlusNet's infrastructure in some way, and something in their network is causing the issue.
They don't support IPv6 particularly well, which is disappointing. We got a deal for £35-ish a month but it's gone up over the contract period to £42 a month. Standard at contract end will be £62.
Overall, we've had no major problems, but I'm 3 months out from renewal and thinking of writing off those three months so I can switch back to Cerberus.