I've owned both and the handle shape of the PG is much more comfortable and secure for me than the M16, though the cutouts in the scales and clip of the PG dug into my hand when gripped hard. Overall, other than the cutouts, I really like the shape of the PG, which could be why I often carry an Ares now. I think the M16 felt a little bit sturdier. If you can handle both that should make your decision much easier, as they have very different feels. You might also want to look at the new M18 series - like the M16's, but with a better blade steel, LAWKS, & G-10 handle inserts. Were I to buy another CRKT it would probably be one of the M18's.
Edited to add - both the M16 & the M18 have the flipper, which has got to be one of the 10 best inventions in the history of the pocket knife.