The Tom Tom Spark GPS watch has been really great so far. I have been using it regularly for the past month for tracking runs and bike rides. The interface is incredibly simple to use and the battery life has been really great - I can usually go a week of general daily use and 3 or 4 runs/rides (GPS on) on a single charge. It is really great for tracking your workouts and being able to wirelessly upload workouts to a digital interface, the TomTom app leaves much to be desired though.
The activity tracking is okay... honestly I am not that interested in it and I am fairly certain that the sleep tracking cannot be trusted. I would not suggest this watch if that is your primary concern.
NOTE: This watch does have a built in HRM, but you can sync it to a chest strap HRM and/or cadence/speed sensors from TomTom.