Good on paper... but the app lacks pretty obvious features. Specifically, it should have a "start," "pause," and "end" function to track your stats on specific days.
Improvement to the app is fairly important, since the HUD is essentially unusable. Even on cloudy days, with full brightness, it is nearly impossible to see it. And the placement of the HUD is quite awkward - you need to look up (away from the mountain), cross your eyes, and wait for your eyes to adjust to see your speed. And...