This discussion has been had many a time. A GOOD pusher or pointman player SHOULD be able to beat an eraser player on par. But an average eraser player may just be as good as his pusher/pointman top equivalent. This does sorta make it OP, but it has it's limitations. I have a struggle against metaLsurfeR (me being an eraser player, him being pointman) because he's genuinely good at it. Now, I'm genuinely good at eraser, but he does get the better of me on many songs.
Vegas is not overpowered. It's just that after about 100 runs, you're bound to get a red splash followed by multiplier. However, unless you know how to correctly hold a chain, those points are almost meaningless. So I actually respect the vegas players who are at the top because I sure wouldn't be able to get that score with vegas.
But if you want balanced competition, go Elite.