I tried a TomTom multisport watch, similar but without the HRM bit, so will just comment on my experience with the rest. It was bought primarily for running and occasional bike rides.
Pluses are that it was very fast at getting a satellite lock, much faster than the Garmin 15 I’ve since settled on. Good clear screen that you can set what metrics you want to see, big easy button to scroll through any others you may be curious about. It was really good having bike or run options rather than just running. And it was really good that you can race your previous runs/rides.
But the minuses are that it didn’t seem to track my position as well as the Garmin. After I upload to Strava it always showed me as being a few metres to the left of the roads/paths I was on. Weird. And it didn’t sync with my phone – gen 1 Moto G running lollipop – so check your phone first if that’s an important/cool thing for you.
You can tell it the pace/speed you want to run at. It then beeps to tell you if you are faster, slower, or at the set pace. You might find this useful. With me this meant it was beeping every few seconds which was bloody irritating so I had to turn it off after two minutes.
And if you’re a Stravaist, be aware you cannot “upload file” from the watch direct to Strava, you need to either sync it through a phone or through the TomTom software on a computer. the TomTom sports website that it uploads your activities to is utterly pointless, but thankfully you can easily sync this to other sites Strava, Runkeeper, etc.
For me, it was the TomTom’s mis-tracking that made me choose the Garmin. Maybe the one I tried was dodgy. Other than that issue I would have been very happy with it.