My SPH-L710 was flashed to pageplus 4 days ago. What i had to do, was go to a stock, unrooted rom, let them do the flashing process, and then restore a nandroid of a different rom. I do not suggest rooting the stock rom after the flash, because it broke my wifi. I did a factory reset using Philz CWM, i wiped the dalvik cache. I rebooted the phone, rerooted, and rebooted. Still no wifi with stock MD4 that was rooted using the GS3 all in one tool.
I restored a nandroid of The Peoples Rom, and Mother of all Roms. My calls, texts, and 3G data all work with both roms. I do not know about MMS, because i do not use MMS. TPR and MOAR are both prerooted ROMs.