just did some shots on a local busy street. the 120p photo mode is nice, people mostly ignored me. some although noticed me, but 75 frames were blasted in less than 1 second, just like taking one picture, very quick. the buffer clearance time was not bothering most of the time, because i spent time looking for the next good frame. v90 cards may cut the time in half. but i am really ok with it, at least for now. it reminds me of the nikon 1 v1, v1 can only do 60p 30 frames.
in conclusion, it is a turbo gopro.