Love my unlocked Note 8 on ATT just have to deal with no ATT features which I'm fine with. The only other negative is we seem to get updates even later than ATT, usually a month after based on previous unlocked galaxy on ATT.
I do have to say that ATT wifi calling on my S8+ seems to cause standby time issues. Side by side my ATT Note8 is much better standby battery vs. my S8+ ATT branded with wifi calling enabled.