I've found mostly good reviews on the Garmin watches. It seems like they last as long as 8+ years although my research indicates that the few instances when they go bad, they start having issues around 18 months of ownership.

The model I'm looking at is about $1000. Not sure if I'm comfortable spending that much knowing that within 10 years, I'm going to have to spring for another, if anything just because the software might be outdated by then even if the watch still works.