But how do you feel about the "modified back stab" - ie the holes in the back of the receptacles that allow you to insert stripped wire, and then tighten the side screw to tighten the "crimp plate" (for lack of a better term) on the inside?

I've seen these on GFCI's for several years now... also on a few receptacles. They seem more secure than the old "knife edge brass" versions ...