I gotta give it two stars because it does work, but not nearly as well as they claim. 90 seconds may be a reality if you have fine hair, or shave your head at least 2X in 24 hours, but otherwise I've never been close to 90 seconds. I shave once a day and barely have the back of my head smooth in 90 seconds, let alone my whole head. I also felt I could never get it completely smooth as I could with a regular electric razor (which wasn't the quickest either but at least got my head smooth). Cleaning is not the easiest and doesn't work as the description says or video shows. I did not get the cleaning stand and just used a small bowl to put water in. It never, ever got all of the hair out as I could see it all over the place on the top of the shaving head; if you could take the head apart it could be brushed clean but alas that is not advised and voids the warranty if I recall correctly. Oh, and do NOT drop the head, as it blows apart exactly as you are told not to take it apart.
Bill Larson gave Skull Shaver a 2 star review