I use unlocked on Att and TMobile sims without issues in past they would take some features away not anymore , Samsung message app on unlocked dont get RCS support but i use Google messagesyep. can attest. in my case, I took advantage of a nice trade-in and got the S21U direct from Samsung. will always be unlocked for me, from here on out.
question: I've heard that unlocked phones don't work as well on AT&T, vs. carrier-branded. is this accurate?