New watches worth it?

Hello! 

I am a proud and happy partner of a 935 for years. I have no complaint whatsoever it works like very well, and the battery is showing no hesitation in 4 years. 

I always use it with a HR chest band, even on my CrossFit sessions. Today I forgot the band at home and went for a run relaying only on the wrist optic sensor of the watch. What a mess...I was even thinking of not logging the session, because such an unreliable measurements affects to my normal statistics.

So my question is. Are the HR sensors of the new watches more accurate? Are they worth in on this regard?

Thanks!!