The UA Ranger's power level is actually fine at Lv. 10+. Where it's considered "overpowered" is at Lv. 1 because of that version of Natural Explorer giving you all those different powerful benefits all at the beginning, when those benefits could stand to be partitioned out one at a time at higher levels.
Anyway, when I DM, I replace Natural Explorer with this homebrew I came up with. It addresses the flaws of both PHB and UA versions of Natural Explorer, I feel.
If I'm a player and someone else is DM, I just use whatever Ranger is available. In my current game I'm playing, it's PHB + Xanathar's.
I really hope the alternate class features Mike Mearls was working on become official, and look something very much like that, yeah.