I have one as well and use it a fair amount.

Overall, I like it; it's a bit big and bulky compared to a regular watch, but not to most other watches like it. I have the metal one with the thin green stripe around the bezel, and like the way it looks.

Setting the time, alarm, and most other functions is very straightforward. The one function that continually vexes me is adjusting the elevation (either setting a known elevation or adding/subtracting feet), though I think that's mostly from not remembering the exact steps, and not that it's that much more complicated than anything else on the watch.

I find it eats batteries more frequently than I'd like (a couple times a year), but then that's also affected by using the altimeter display and compass, which take more power than when the watch is just showing the time.