Just C&P my post from Reddit in an attempt to save anyone a few headaches...
This goes to anyone who likes loading custom roms on their GS3. If you ever have to get a warranty replacement phone make sure you check the model number. It appears that VM is starting to send out and/or sell the tri-band SPH-L710T model now. That's great if you're in an area with Spark service but not so great if you load roms as the radios are different. Loading any roms made for the L710 leave you WITHOUT working radios. Luckily I noticed on my son's replacement phone. He is rooted but we'll have to wait for a Lollipop rom.
This goes to anyone who likes loading custom roms on their GS3. If you ever have to get a warranty replacement phone make sure you check the model number. It appears that VM is starting to send out and/or sell the tri-band SPH-L710T model now. That's great if you're in an area with Spark service but not so great if you load roms as the radios are different. Loading any roms made for the L710 leave you WITHOUT working radios. Luckily I noticed on my son's replacement phone. He is rooted but we'll have to wait for a Lollipop rom.