Actually, oops. I heard they do not support the US frequencies before but forgot. Sorry.

I have a Xiaomi Redmi 4G (codename: Dior) that is 3+ years old. It works on T-Mobile.

That chart is helpful. I would also read the reviews of the phone and check if the phone says "Global Edition" or "Global Version" to also check compatibility.

I use the Mokee ROM. It gets regular updates. But, the Huawei Ascend XT2 feels much faster with a longer-lasting battery.

I recommend checking out https://bit.ly/2RIt4MF I've purchased multiple xiaomi's from them and their customer service is fantastic, I've always received my phones within 9 days.

Check out the note 6 pro, 4gb ram 64gb storage.

Also look into the /r/xiaomi subreddit as there's a ton of information on compatibility and satisfaction.