$500 - 600? I would recommend HOYT. I think mobowhuntr would also agree. I have tried out Hoyts and thought I had died and went to heaven. They are that nice! But I didn't want to spend that much $$$$ on a bow, so I got their secondary line called Reflex, which are equally nice.

Mobowhuntr could give you all the advice and specs on Hoyts, I am sure....