I use the gear s2 with the note 5. I haven't found any problems with it. My only issue is I can't adjust the screen timeout time. I wish it would last at least 15 seconds for work purposes, but I make due.
The S2 problems that I mentioned relate to the screen timeout behavior and the unreliable weather updates. These have been extensively (and appropriately) discussed in the Gear S2 forum.
As I said, the Note 5 itself hasn't caused any problems with the watch.
I actually have three smartwatches, Lg (first gen),Gear (first gen), and gear s2. I think the android wear os is clunky and annoying. Of the the watches, I definitely like the gear s2 the best.