Celio, thanks. I hear what you are saying, and it's worth many many dollars more to me than .02.
I know what you mean by sitting back. Here's some history: It used to be that I'd set up with my knees behind my toes (I was overly-focused on engaging the posterior chain). I corrected that on the descent, but on the ascent I'd push my butt back instead of up -- my knees would end up behind my toes again. I was engaging the hams and glutes too much, and not using the quads effectively. See the following thread for a related discussion (I wasn't involved in the thread):
Since then, I've focused on keeping my knees in the correct position on the ascent, and I've managed to accomplish that. But I need to compensate for the changes I've made to knee position.
When I had the knees too-far back, I'd be forced to lean forward enough at the hips (i.e. decrease the angle between thigh and back) to keep the bar over mid-foot. I think I'm still leaning over as if my knees were too far back, and I need to correct that habit. When I correct that, the weight won't be so far forward, and I think that I'll automatically sit back correctly, as you suggest.
Thanks for listenting to me think out loud. And thanks again for your feedback!