I have owned a number of OnePlus phones and have been very happy - OnePlus phones come with an OS (Oxygen) that's very close to stock Android, and the company is very friendly to you running a custom ROM if that's what you're looking for. Thought the price has gone up through iterations it's still less than a "Flagship" phone, but with really nice stats, especially the "Pro" models. These phones use many of the common cell "Bands" (3/4/5G/LTE) - I am on AT&T, and my parents are on Cricket - the phones work perfectly with both providers. We buy our phones direct from the oneplus.com site and swap the sim over - no need to let the provider know what we're doing as frankly it's none of their damn business.
The only downside I will point out is that we don't benefit from WiFi calling, though the phone is capable of doing this AT&T (in my case) chooses to not offer this functionality. It's not a phone limitation, and though I have had MANY calls with AT&T, they have the stance that enabling this on accounts with only the devices the sell is a "benefit" customers get. We have been given a free microcell as well as upgraded units to live around this limitation in our home.
T-Mobile just started carrying this brand in the last 2 years, but not being a T-Mobile customer I can't say how hard they push it, or if it was a one-and-done event, so this might not "Technically" qualify as not-recognized, it's still certainly not mainstream.
(post is archived)