I put my 4S on Solavei. It works great so far. It runs on the other major GSM carrier (not AT&T) so it is not perfect. But I have to admit a couple reasons I did it. 1) $49 Unlimited Voice, Text & DATA! and I was comletely FED UP with AT&T and their $120PLUS bills. 2) There is no advertising for Solavei, so they use the money to lower service prices and it's subscribers get to earn based on if their friends signing up. 3) No Contract! if you don't like it, you can leave!
That is my 2 cents, so if you want to join you need a member to get you in so here is my site. Hope you like it!
http://www.saveoncellservice.net
or sign up directly at
www.solavei.com