We switched to Pure Planet a few months ago. I was a bit worried about using an ap only company but have been really impressed. The switch went through smoothly and all we have needed to do is enter our reading every month. It's definitely saved us money so far too.
If anyone is interested in swapping I have a referral code that gives you £25 when you sign up:
purepla.net/rfm/gQpgpBFd