dotman has one I believe. Not sure how much he has used it though. Your concerns mirror mine. Plus, don't you have to have it paired with a phone or remote to change settings? For some reason It doesn't even have an LCD to tell you what the current settings are, correct? So, any time you wanted to change a setting you would also be draining the battery of a remote or phone.
I have a Hero 3 Silver and a Hero 4 Black. I don't really find a need to have a smaller form factor as even in their waterproof cases, they are still pretty small.
All that said, I think you can get them for a steal now on certain deals so you could probably get two for what a Hero costs. Just depends on how you will use it and how much fiddling you want to mess with to change settings and all that.