Just arrived. Got just one to be cautious - in case the thing fails on a long descent I still have one mechanical brake.
Mounted in front on a 700c adventure bike with a Fox suspension fork and SRAM rival brifters.
Nice hardware. I like the look. Seems lighter than the Hayes CX5 stuff I have. Easy install. Do read the brief directions. Cable is run far inboard, less likely to get snagged on bushes, I guess. Using with a Shimano 160mm ice tech rotor. The TRP is compatible with the ice tech 160mm rotor, unlike Avid and especially Hayes mechanicals which hit the Shimano spider arms. (The TRP steel rotor that comes with the brakes seems light and elegant, just haven't tried it yet).
First ride, just a spin around the neighborhood, with one brief steep (15%) grade, AKA my driveway, but no sustained descents. Initial impression, not fully broken in: Does not have the initial "bite" of XT hydros, which is OK for road use. Power is good, already a bit better than the broken in Hayes. Modulation seems good. No brake rub or chatter so far.

I won't be able to ride in the mountains for a while due to other commitments but as soon as I can do a 1500 foot steep, curvy, lots of braking descent, I will post again.
If I live