I am moving from an alltel/verizon plan (with old non-smartphone device) to either Tmobile for the Galaxy S 4g, or sprint with the EPIC 4g or the EVO. Anyone have experience with these phones? (i know sgs4g just came out but is practically identical to vibrant) Anyone have recent experience with both phones/carriers and speeds/features? Was going to go with the 4g from tmobile but found out I now have a choice between the two companies to add on to unlimited family plans. Any imput?