Maybe I'm not seeing clearly enough, but when I shoot portraits near to 1:1 (bellows at about 800mm) using a 450M Nikkor with the 11x14 I don't notice the perspective 'distortions' you might expect with a wide angle lens up close. The nose, for example, doesn't seem larger in proportion than normal. I've wondered why this is but don't have a clear answer.
One thing I did learn was to focus on the tip of the nose rather than the eyes. Given the short DOF if I focus on the eyes the tip of the nose is then out of focus. If I focus on the nose the greater DOF behind the focussed upon area catches the eyes too.