I would disagree that the head position is critical, but then you have to be critical about your head position if you want to avoid parallax problems with almost any scope..
the sides of the scope practically disappear, making it easy to orientate yourself into the middle.
It has a lovely crisp sight picture, and the half mildot ret is great, and you have a full 10x power. I think the optics are better than the Bushnell Elite 6500.
The windage turret being easily moved by a peg is the one downside for me. The stupid little allen key for turret re-zero is pretty crap too.