Sounds a little like my new SO beats me up a LOT less than other's I've had. "Overall not a bad carrier" is not a ringing endorsement. Not to mention that its an even better carrier if you bring your own phone.
I'm not trying to convince YOU to choose an option that eliminates the downsides of a carrier phone, just mentioning it for others who haven't decided. You have a good list of "not so bad's" and "maybe won't happen" but you left out others like "AT&T probably won't delay or prevent important updates", etc..
Well... Unlocked or not... I have not had an issue with att... No matter what phone I have had with them. I get the best GSM service in the us with att... I have got my updates... I mean is it just the 830 that people are crying about with aloe updates? I had had android, iPhones, ans windows phones... Focus, LG with keyboard, 900, 920, 1520, 635, 640...
With so many hardware variations ans old most being unpopular, updates under this and other carriers were a little hindered.
Thankfully, we are all in a better place with Microsoft and software updates.
The phones purchase location, variation of hardware, or manner of payment... All just about the same in the end...
Att version has pma which may prove to be a good thing if it ever takes off... But at least it has the qi for all my other chargers I have now... Now I have to decode if I want to get this phone or not.