What if you keep it like it is BUT give the option for "advance mode"?
If you press the "advance mode" button you will have the 5-star way of voting, if not it stays as it is!
So the "lazy" users will not be affected and the advanced users will just click on that button!
That "advanced mode" can get more advanced at any time (more options) without the fear it will heart mass adoption since it is targeted to advanced users only! (they choose it)