the k/vstation and supernova share very similar sound functions - the k/vstation has tri and sin wave - the supernova has the hardness function to turn the square and saw in to them , the main difference between the supernova and the vstation is the fm mode, formant/skew , vocoder , the multiple filter types and the mod matrix (if we are not on about the multitimeral functions)

the reason i said it cos i have the supernova2 here and was comparing em the other day , i dont have a kstation at hand to compare them - all i can say is that the vstation is very very impressive soundwise - in someways even better than the supernova

the ks4/5 on the other hand has a shitload of extra digital waveforms in the oscs like the virus/waldorf q etc so really can do sounds that the supernova/k/vstation couldnt even dream of so nerrr

:)