Dominick Layfieldwrote a review of TomTom Runner Cardio Watch on August 25, 2015
Familiarity: I've put it through the wringer
The best thing about the TomTom GPS watches is their size. They are nice and slim, so that you don't walk around feeling like you're wearing a brick on your wrist. I also think they look pretty neat, but that's very subjective. Generally, the watch is intuitive and easy to use, the display is crystal clear, and everything works as is should. Bluetooth syncing with your phone is (finally) working pretty smoothly on both Android and IOS devices. Only real downside is that the ~9 hour battery life is not enough for long ultra races. However, that's plenty long enough for most runners training and competing in most events. The optical heart rate measurement works very well nearly all the time (even HR straps have hiccups and occasionally produce bad data), but does require that you cinch the watch fairly tight to your wrist when you're exercising. The TomTom MySports website is somewhat basic, especially when compared to Strava or Garmin Connect, but provides functionality to auto-sync your data with most other athletic sites, so I don't consider that a problem.