I bought my Rhythm+ June of 2017.
Ok, there are a ton of negative reviews on here, which I believe are a tad unfair. I sync the strap with my watch (presently a TomTom Runner), and it just plain works. Occasionally the HR will measure low, but during the course of my runs, it is rock solid. As for RhythmSYNC , I only use it to make sure that my firmware is current (which has only needed an update 1 time - I’ll get to that in a minute), and to check the battery level to see if it needs charging. I basically charge the unit once per week.
I am actually now on my second Scosche HRM.
The first one (purchased in 2017) needed a firmware update, but (on the ORIGINAL app, not this one) following all of the guidance from RhythmSYNC and from tech support, it simply would not update. The tech support team advised me that it wasn’t really a necessary update, but if desired, they would replace my unit with a new one that had been updated. I opted to swap it out and have had no issues since. (This was in July/August 2019).
Do I wish we could do more in RhythmSYNC ? Sure, but my main focus as a distance runner is knowing what my HR is doing during my training and long distance runs. Anything more than that is just a bonus.