Summary: the 910XT watch is excellent and does the job. Together with the Garmin connect you can easily track performance and progression the hart monitor is worthless and stooped working after less than a year. I try replacing the battery but it doesn't work.
Summary: Second one, first had the "quick mount". The mount was fine, but it allowed me to take the thing off my bike, set it down on the car bumber and forget it and drive off. Seems to take a while to aquire sat signal. Can't tell breast from back stroke (gets free style well). Old one started loosing the vibrate alert. Had the 610, which was not waterproof. Have used this in open water ocean swims and works fine (no HR recording, as expected).
Works very well, looks ok, overall pretty much met expectations!
21 April 2014
Summary: Ive been using for more than a month now for swimming and more ocasionaly running. It works. Simple as that. Also it gathers more data than an average athelete would care to use. If you are more advanced than its all there. I like that I can see the evolution over time of metrics that would be nearly impossible any other way. Depending on how you swin, you will have to make small adjustments so that your laps are perfectly counted.
Summary: I am new to the world of triathlons and this watch is working out great. The heart rate monitor is very accurate. I tested it manually and using the HR monitor on a treadmill and stationary bike and it agreed with all. The watch works well and it mostly intuitive. It's not as easy as an iPad, but it wasn't too difficult to figure out how to change the fields being displayed. A lot of people seem to have trouble finding the time: there is a field that says Time of Day.
Summary: I have been using the 910 for about 8 months now. I've done a 1/2 iron man, several smaller tris and 2 marathons with it. I have also used it in the pool during training and competition. I have been very happy the performance so far. I have not given it a 5 star rating however for a few reasons: the gps pace on the run setting tends to jump around a bit. This is no worse or better than the 2 previous watches I've used but it can be irritating.
Does just about everything one would want, but defective barometer was a hassle.
23 January 2014
Summary: The only drawback was that the first unit had to be sent back due to a defective barometer. That also meant I had to reprogram and resync the entire thing by hand. This includes the slow entering of bike names, etc. It would be great if this could be done on a computer and then the settings transferred. Also, one would expect that the factory could automatically reset the settings, or at least, do so manually since the whole affair was their fault.
Summary: I had the 405cx and upgraded to this one. I like everything about it apart from the Heart Rate Screen is shared with Altitude and Altitude is the prominent part of the display with the HR tucked in the corner. I don't really care what my altitude is when working out but I do care about my HR.