I’m using a Garmin 245. I’m using it to track sleep/ resting heart rate. Finding it does the job for me, and am happy with battery life and accuracy. Not really doing any running at the moment. I’ve no evidence it isn’t accurate on the bike (which is often a complaint), but tend to use a strap for that.
Planning on getting a 530 for the bike so I can maybe use more of the first beat stuff that both together would give me.
From what I understand, optical hrm’s have continually improved. A lot of people seem to have been put off by the initial/ early iterations.