My wife bought me one of these watches last Christmas. I am a small guy, and the watch does not seem overly large to me. The altimeter on the watch is consistently accurate, but started to drift slightly for me over 13,000 feet, but overall I am very pleased with the altimeter. The barometer works well also for weather prediction on overnight trips. The compass also works very well for my needs, and I don't carry a old school compass anymore. You can also set five alarms, and set elevation alarms (pretty handy).
Overall, the watch has far exceeded my expectations of what I thought a watch could do. All of the instrumentation has been accurate on my particular unit, and has been independently verified by my hiking partner's much more expensive GPS.