Slightly disappointed. Haven't installed but read an article that the rhythm monitoring doesn't work if you tell it you've already been diagnosed. Now, in my case I know when I'm in AFib for example cause I get rapid heart rate with it. Many people don't, so if you've already been diagnosed but you don't feel you're in it when you're in it, it would be really nice for the watch to be able to say something about it. As long as I can still use the EKG feature though I can live with it. If that won't work either, well, let's just say there might be an AW4 listing on ebay or something very soon lol. (ok not really, but the new heart stuff was one of the big reasons I switched from FitBit)