In reply to:
As for UKFSN being a one man band operating from a semi-detached house in Hertfordshire, you only have to look at the likes of Plusnet to realise that a nice HQ doesn't necessarily imply a good service.
I don't doubt that, and I'm not inferring that a large office is any guarantee of superior service, or I'm not inferring that you won't get good service from UKFSN.
It's down to just one thing - if I had to bet which ISP I would bet on still be here in 5 years time, my money would have to be on Zen. That's my
only reason for recommending them over UKFSN.