I've been on it for about 18 months and I think it's great. There are some problems (e.g. the pages for purchasing the monthly package occasionally don't work, and it seems to have forgotten the fact that I've got my purchase down as recurring at least once, meaning that it ate into my credit).

But for the saving compared with most networks, those pains are almost irrelevant and you can get even more money off by referring people - it's £5 back for everyone who you get to sign up.