you just have to be way more specific about what you think the problem areas are. this method will give some distortion across the top of the foot and front of the knee, but not enough to worry. the heel, which gets a little more pixels than perhaps it should, you can either cut into that or just avoid small details (which will be crushed). in general though you haven't been attentive to the pixels on the texture so as long as they are all roughly the same size you hardly need to have perfect pixel-shape integrity.
on any decent res (256+), distortion due to the pixel-warp is nonexistent to a good texture artist because he sees in planes, not pixels. what follows then is only natural - that those planes become squared so as to maximize useage. on rare occasion fine lines cause problems, but this is generally a sign that the res should increase, not that the artist should map his faces more planarly.