I've had my Cobra 1 for about 4 years now and love it.
It's always been reliable and held up well and never failed on me. I also have the Sk7 compass, which I'm not as crazy about. I've had 3 compasses and the first two developed leaks. But perhaps Suunto has got that problem fixed now, since I haven't had any problems with the current compass.
I've also used the Quick Disconnect, but I found it was not all that useful and ended up selling it.
the one flaw/problem is the PC interface. It is sometimes a hassle getting the thing to make the transfer. I keep having to jiggle the connection to get it to work. If they had a better system for that, I would have no complaints with this computer.