The Sandstone one is really nice looking. I look forward to reading comments on it here.
Since I don't know much about OnePlus yet, if
I were to be tempted by a Chinese low cost phone at this point, it would have to run pure Android on the Android One program.
@deany recommended the Xiaomi MI A1 and though it has very few reviews on Amazon they're good among the T Mobile users and it should run on AT&T. $274. Wow.
I may pick one up at some point just to see what I can get for a truly palatable price point.
I already had the privilege of seeing the champagne and caviar side of things with the iPhone X for a month. That was fun. It wasn't for me a viable choice in the long term, but I am glad I got to find out.