Samsung Galaxy S7

I can't seem to find a simple direct answer to this question. I switched to TM and bought an unlocked refurbished S7 SM-G930T. I hated the service so I went back to AT&T. The phone seems to be fine operating on AT&T's network as far as I can tell. Opinions vary widely in searching for an answer online. Can I get some facts here?

I really don't want to take a loss on this phone & search for a G930A unless there's a noticeable difference in performance or connectivity.