Best ISP I've ever used
6ms ping and 1G up/down, pretty much as it always is and always has been (I really do mean >99.9% of the time) for the ~3 years I've been with them.
Honestly they're genuinely the best ISP I've ever used by a long, long way, and I've been accessing the internet since the dark ages when it was via a dial-up modem that squawked at you, took a minute to connect, and if it did work my modem (yes mine, ISPs didn't give you one back then) was 9.6kbits/s.
BT, Pipex, Demon, Zen, PlusNet and many more I've used over the years and none of them compare to YF. YF are not perfect of course, service does drop very occasionally, and they make mistakes (they failed to attach my old number to my voip when first installed), but every single other ISP I've used, both professionally and domestically, has been worse.