Don’t take anyone’s opinion on how good or bad the wrist and chest straps are. I think it’s a very individual thing. The wrist sensor was the problem for me. It had to be worn so far up my arm for a realistic reading it would never stay there. The first ten mins of readings were so bad, greater than 220.
My watch was saying I was spending too much time in the red. Max HR was 218 on a ride. It had my fitness age as 74.
I started wearing the chest strap and low and behold, only seconds spent in red zone, max HR 151, fitness age 20. Now I can use the PTE, EPOC and recovery data.