My Suunto altimeter started acting wonky, so I reluctantly did a search and just got a Casio triple sensor — of the bazillion of model variants I opted for one that doesn't do radio time updates, and isn't solar powered. Maybe I should have gone for the solar power, however, as in reading various user reviews someone had commented about the batteries being replaceable … a key factor for me, not having to mail the unit back to the manufacturer or third party.
Well, it turns out that someone has posted some detailed and possibly tricky instructions for replacing the batteries, but the documentation clearly says you need to mail the unit in. It's definitely NOT designed for user replacement of batteries, much less "field replacable" as my Suunto is.
So caveat emptor, FYI. The particular model I have is the PAG-40.
Initial reaction is that it's heavier than my Suunto, nicer overall controls (direct buttons to get to altimeter, temperature, compass). Unlike the Suunto there's no declination adjustment for the compass (but a turnable compass ring that doesn't strike me as much more than "possibly cool-looking to somebody …". The separate button on the Casio for turning on the light is nice, I would periodically forget on the Suunto which button I had to push and hold in the middle of the night, particularly since the unit is mostly symmetrical (picking out for sure *which* button to push and hold, and not inadvertantly reset some functionality).
I'm not a fan of how the Casio unit displays the time in HH:MMSS format, with the seconds digits immediately adjacent to and equal size as the minutes. No big deal, just seems like a poor design choice to me, maybe I'll get used to interpreting that over time.
The battery replacement is the big issue. I almost mailed the unit back, but instead downloaded the somewhat tweeky/geeky replacement details that I could find and am gambling that when it's time to replace the batteries that (a) I won't be 3 months into a 6 month trail, and (b) I can actually accomplish it even at home in a clean environment with tweezers and tiny screw drivers available.