For me I found the Suunto easier to use than the Casio Pro trek. The features of the Suunto Vector and Pro Trek are the same but I did find the altimeter on my Suunto more accurate than the Casio over the course of a day's walk. With the Casio I would have to adjust the altimeter more frequently than the suunto to ensure accuracy. Also the digital compass on the Vector is more accurate with the ability to adjust for mag variation as well. I have the Advizor which is basically the Vector with the addition of a heart rate monitor. As I've said, I'm very pleased with mine and would not go back to a Pro trek but that's me.
