I'll add my two cents here. I wear a Suunto S6 and it is great. It has a cell phone like menu on it that you can scroll through and change many of the options. It has a clinometer for slope reading which works great for avalanche hazard assessment, and low angle rescue assessments. The reason I bought it though was because it has an altimeter lock on it. Basically you can set it so that any change in air pressure is a change in alititude 'use alitmeter' or you can lock the altimeter and it will measure any change in air pressure as a barometric pressure change and graph it as a trend. It will also convert all your barometric pressures to sea level for your current altitiude.
I like it because I can set it to alti, climb all day, then when I bivy, I switch it to baro, and it will log the borometric trend all night. In the morning I can see what the trend, look at the clouds, wind and take a wild guess at the weather for the day.
I also really like it because you only need one measurement to set all the rest. For example if you know your current alititude from say a GPS or a map, then you can input that in and it will give you the current actual baro reading, and will also give you the converted to sea level reading. And vice vera, if you know your baro, you can set your altimeter.
If you want you can plug it into your computer and print out a graph of you elevation gain and loss over time, but I could never be bothered. If you are a skier you can catalogue your runs, and it will give you a speed and average run speed too.
Anyway, I swear by it. I take it off when I am rock climbing (usually) so as not to scratch it, but I've done many jumps with it on, and it is still with me. Very durable. And the best thing; it is smaller than the Vector. I hear the X9 is good - it has an internal GPS, but I would never front the $900 price tag.