I have a Polar FT4 that I used for almost a year. It does have a chest strap and after the first couple workouts, I never really noticed it. I got it before I was CrossFitting when the class I was taking as based on interval training. I wore it when I started CFing but I'm not sure how accurate it was due to the SWOD components of the class. Most say that a HRM is not accurate for strength training since you're heart rate isn't elevated like it is during cardio session. The main thing I didn't like about it during CFing was having to wear the watch/receiver which I felt like interfered with wrist mobility during lifting.

The only other thing I have is a FitBit One. It's nothing more than a fancy pedometer and I would not trust it for any other workout than running/waling. It's calorie calculations are based on activity and sensors and as such has given some wonky readings in the past. Once it reported that I climbed 50+ flights of stairs when all I did that day was drive around around visiting family. This morning when I woke up it said I had taken 50 steps since midnight... I was in bed at 11 and did not get up during the night.

Hope this helps in some way.