Set up correctly it’s fine. It can be B screw sensitive, as well as chain length sensitive. I would recommend a RadR cage as this seems to smooth out a lot of the issues. I used an XT cassette, Hope T-Rex, RadR cage, Zee FR mech (although the RadR cage is longer than the Zee one, which is no bad thing), Raceface NW chainring and Saint shifter. Shifting was precise and reliable, with no chain drop on back pedalling. All in all a great setup.
The simplicity of 1X10 is compelling. You ditch weight, too. I found 32 teeth up front and 11-40 out back fine for everything, including the Alps. This was on a 26er Trance X.