I still use my Bushnell and/or Leupold rangefinders mostly.
The ShotScope one is fine… except that the eye cup is pretty "deep" so if you wear glasses to play it's a bit of a tunnel, like a rifle scope. You have to be aligned quite precisely to look down it, or else you get a strong vignetting effect.
The slope feature and the measurements seem just fine.
Plus, tapping your club to your rangefinder (if you put the GPS thingy there) is weird… particularly for putts. But you don't have to use it for shot tracking, I guess. You could just enable "GPS" mode.