Here are my detailed reviews of the Garmin multi-sport watches. The 910XT, the 310Xt and the older forerunner 305 (now discontinued but still available to buy new)
The links to the reviews are below, one thing I would say is that the prices seem to have come down a lot recently (early Dec 2012) so amazon is a great place to grab a bargain.
- Triathlon/Duathlon Review 910XT
- Triathlon/Duathlon Review 310XT
- Triathlon/Duathlon Review FR 305
- Triathlon/Duathlon Review Fenix2
Functionally the 910XT is almost the perfect triathlon watch. But there remain a few glitches. The 310XT is a very competent glitch-free solution but it lacks some swim functionality and metrics. You just can’t use the 305 for swimming but otherwise it’s fine.