I've been a member of Pureplanet for just over a year and as I have always jumped ship once my 12 month contract is up to chase the better deals for new customers, have recently looked in to switching and there is no real difference in price with the best offers for new customers I could find. We have a family of four and are all heavy electricty users, which is where we save money with Pure Planet, but if you are a low electricity user, I would recommend doing your own comparison using your last years KW usage as one of the other Energy suppliers may be better value for you.
If you are thinking of switching, just like everyone else on here, I have a referal code which will earn you and me £50 if you complete the switch:
purepla.net/rfm/cFcpFdc
Kind Regards
Mark