No issues whatsoever of any lasting consequence. Live blogged a 10 day Las Vegas trip, complete with photos, both on cellular as well as two different resort companies wi-fi (these did ask me to relog in after a time but that's a daily procedure). Had an iPhone 8 plus alongside as comparison. That was a pretty good stress test, as well as my home situation where cell is spotty (in a valley, etc). I played with this on acquisition, too.
If this certified internet idiot can liveblog a 10 day Las Vegas trip when using his cellular phone-as-tablet/only computer in stable for the first time (I always had another way. laptop, tab, etc) then trust me this phone is working A-OK. In addition, when I got this in my hands at initial release, I read here and did everything i could do to prove this phone was defective and should be returned in favor of some other option, be it Apple or otherwise, and couldn't accomplish that either. This is not to minimize the issues others are having - but if my phone doesn't show a problem, it doesn't show a problem, and it gets into the realm of audiophiles reading spec sheets rather than listening to the gear to make their evaluations.
I did have some glitchiness uploading photos and a few other things in the 12.0.1 but a restart took care of those, and the 12.1 seems even more "out of the way" in that sense.
I suspect that my phone/carrier/whatever else in the ether came together as it should. This again does not mean that others aren't having issues, but I don't typically return product that works as it seems it should.
