I ride ~120 days a year, and bring out the gopro on maybe a fifth of those days. It's mostly useful for me as a tool to track progress (those videos from three years ago sure look like ass now!) But it's been handy to have for helping teach some friends how to ride, and filming others adds a whole extra dimension to snowboarding that can be a lot of fun.
That said, it's a fair bit of work to get footage that's not horrific and put it together into a package that someone may actually want to watch, so if you expect to make sweet edits that everybody loves, be ready to spend some serious non-riding time on your videos. I personally have discovered that I don't have the patience to do a real edit, so I've mostly just used it to cut clips that are rad enough to not be total trash.