I've had my watch 24 hours. My initial reaction is that I made a good buy (FYI, there are many refurbs on the market for a very good price). It is perfectly sized for me-a pretty large dude-at 46mm. My beloved pathfinder is 47mm I believe. The watch has a nice heft, and the ring rotates nicely and it's functional.
I think it will take some time to use everything and set everything up, but that's cool.
As a replacement for my Garmin VivoHR+, which is about as visually appealing as a damned fitbit, I'm really happy with it.
The only snags thus far are the phone passing notifications to the watch for nothing-a chime goes off on the phone and nothing shows on the watch. I'm sure by limiting some of the notifications on the watch, this will go away over time.
The other snag is that the band for the watch is pretty small. The Garmin came in a regular and XL model, and the XL has a more-than-large-enough band whereas the Samsung's band feels pretty nice, but it way too small for me and I've had to order one from Amazon.