R’ Abadi holds that any electric shaver is fine because it can’t really cut at skin level because if it did you would get nicked. I don’t know if that’s true or not but it makes sense.
I once heard from a respected Posek: All shavers are completely Muttar and all are an Issur D’Oraisa. It just depends on how hard you push it.
I once hard from another respected Posek, B’sheim R’ Shlomo Zalman Auerbach: If after shaving you feel your face against the grain and can feel your hair then it’s okay.
I find all of these Shittos quite interesting, actually.