Rating: 4 / 5
This is the "first" and industry standard in a watch, altimeter, compass, barometer and whatever else it does -- according to my research. It is a kind of wrist computer. It costs around $150 - 200 new, I have not checked eBay for them or looked for one used.
We just got one of these.
Actually, I got it for my partner. She is always trying to tell me the altitude of a place ... which used to lead to a lot of debates. And, having the ability to determine the altitude without a GPS, which I think of as real cheating when trying to UL trek or just "be" out there, is a plus -- for more than navigational or geographic purposes. It is a safety function.
The altimeter part is useful in locating our position on a topo map. For example, we once hiked from one lake to a series of lakes in the Lassen Wilderness area. After climbing a good distance, being tired, we really couldn't tell exactly which of several lakes we had reached - we had never been there before. One lake was at like 7,000 feet, one was at 7,200 - it made a big difference in determining if we had a ways to go to our destination or not. (I had brought along a clunky altimeter bought in an auto parts store for putting on your dashboard and determined the approximate altitude.) Voila, I knew which lake it was and, thereby, knew exactly where I was on the topo map.
So knowing the altitude is great when we are out there and have never been to that "there" before. It is safer to know the altitude, for example in the winter here, whether hiking or driving around, because it determines the projected snow line and freezing line.
The other aspect making it a great trekking tool is that you don't just have the altimeter you have all of the other functions, including the watch, timer, compass, etc.
The only reason I am giving it a 4 is that it seems clunky in size to me, it has a built in rubber type band which I think is going to wear out, and most importantly the face on the one we got has a dark background instead of the light background shown in the Suunto pictures and is a little hard to read with my now well used and oldening eyes in a glare -- the sunlight glare, not my eyes glaring.
See it at: