ok. lets look at it this way.
i wont condemn it without seeing footage, taken at any of those resolutions.
but 4k at 12fps... those pictures better be sharp, i just looked it up, 4k is roughly 8mp. so any single frame could be a decent picture if you take it out of the shot... lets say you want to capture your kids sporting event. if the camera is good enough, you could shoot 4k (12 8mp pictures a second) instead of hoping you can take that 1 picture at the right time.
but thats not what im looking at and likeing. 720p at 120fps... if that camera can focus well... this would be awesome...
but like i said, it all depends on the quality of the camea... and something that small and cheap... im calling bs on the quality aspect, it just wont be there for serious use, but be decent for where ever a small camera and only a small camera can fit.