If I were a runner, this would be a must. I don't run anymore but great for swimming. HR function works fine wo a strap. Interface with Garmin Connect Outstanding for tracking activities.
Another outstanding Garmin product. Battery lasts about 3 wks.
Purchased to upgrade my 920xt. This thing is light, looks good, and gives you all the training data you could ask for. Also looked at the Fenix 5 but glad I went with the 935 -reduced weight and bulk. Plus it costs less for all the same functionality. The watch still looks very good as any everyday wearer. I spent the extra $8 to buy a screen protector for this as I did read some post of the screen scratching.
I have had the Fenix 3hr, Forerunner 235, and Vivoactive Hr. This is simply the best watch I've used. Battery life is long and a lot of useful features and running metrics. Last year I biked a lot but this summer I've been mostly running ultras.