Aim point-how far forward?

[exgolfpro]

I understand the idea behind the Aim point. I had always done this with my wedges, but didn't know how to verbalize to others how I did it. So, now I am trying to integrate this point thru the rest of the bag. My question is..how far is too far forward? I get pretty good results while using my irons if I drive my hands at a point a good 12-15 feet in front of the ball. The only visual I have seen of the aim point is in Bobby Clampett's book Impact Zone and he shows it being about 4-5 inches in front of the ball. Am I overdoing it?