The swim stroke tracker is hit-and-miss for me (sometimes guesses the wrong stroke and length points) but that probably says more about my swimming (which is awful) than the watch.

But I can definitely vouch for the excellent battery life, resilience to water, and usefulness on a bike laden with sensors.

The only gripe I have is that you can have multiple sets of bike sensors but not anything else. That and their approach to OS X software basically being "well, be grateful you're only 2 years behind the PC and that we acknowledge you at all."