Based on excellent reviews at this forum and others, plus stellar Amazon reviews, I got the Diztronic. I think it's awesome. The one I got is black with a matte back and I much prefer the GNex *with* this case on than without. It is far more secure in my hands. Thanks a lot to everyone who recommended it! It fits the extended battery perfectly, btw.
Haven't tried the screen protector yet, as I am giving the Boxwave a few weeks of a trial run. The Boxwave seems to be sticking down on the edges a little better as time goes on.
For anyone that wants a super-slim case, beautifully-made, that accommodates the extended battery, look no further. Diztronic. Done.