Ascent and descent information will be automatically corrected once the data has been uploaded to Garmin's Connect platform (available for Android, iPhone and on the web), but that doesn't help athletes looking for real-time data.
The 735XT also lacks a quick release kit, which is used to quickly move the watch from your wrist to your bike during competition. The Forerunner 920XT, which the 735XT succeeds, includes both an altimeter and quick release kit, as does the more expensive Fenix 3.
Battery life on the 735XT may be an issue for some slower triathlon competitors. The watch will last up to 14 hours with an active GPS signal and heart rate tracking and while that is an increase from 11 hours on the 235, it may not be long enough to complete a full Ironman competition, which consists of swimming 2.4 miles, biking 112 miles and running 26.2 miles. Battery life will be reduced even more if Glonass, the Russian equivalent of GPS, is enabled.
A special UltraTrac mode will extend battery life to 24 hours, but there are sacrifices. The UltraTrac mode disables the heart rate sensor and reduces how often the GPS is pinging the satellite.
As an everyday watch and activity tracker, the 735XT will last up to 11 days. I typically saw between five to seven days when using GPS for between 45 minutes to an hour each day. It was more than adequate for me, but your mileage will vary depending on how frequently you workout.
Other watches to consider
The 735XT is an exceptional triathlete watch and I really enjoyed wearing it. It's comfortable and it has almost all of the features you would need to seriously compete. But if you rely on accurate altitude information, a quick release kit or looking for something with longer battery life, the Fenix 3 or Fenix 3 HR may be worth the upgrade.
Then there's the older Forerunner 920XT, which Garmin is still selling for the same price as the 735XT. It lacks an optical heart-rate sensor and is rather bulky, but it's still one of the best triathlon watches available. A discounted 920XT could be very appealing.
If you don't have plans to compete in a triathlon, you should save money and get the company'sinstead. It lacks some of the more advanced features and doesn't include interval workouts, but it's still a good multisport GPS watch for casual users.
If all you do is run, check out the Forerunner 230 or Forerunner 235.