I like G10 so much more than FRN, it's not even close. G10 has a real quality feel to it, it feels like you're holding something nice and well made, as opposed to FRN which always feels like you're holding a cheap piece of plastic. I usually polish up the scales on my G10 handled knives (my Cara Cara included) so that they look and feel very similar to smooth linen micarta. It's almost like having a bone or stag-handled knife, but much more durable and less expensive. I'm a real guy, not a "high speed low drag" ninja dude who jumps out of helicopters, and I've never had a knife slide out of my hand because it was all slippery from the blood of my enemies and it's highly unlikely this is a situation I'll ever find myself in. Smooth handled knives are very nice and well suited to real world, non-hollywood use.
Chemically, FRN and G10 are not all that different. Both are glass-reinforced polymers. FRN is Nylon 6 and G10 is Phenolic resin (a much older, less sophisticated polymer). I think the long glass strands in the G10 give it greater dimensional stability over FRN, but you can't really cast it or mold it like FRN. It's because you usually have to bolt slabs of G10 to a steel liner that make most G10 knives heavier than FRN versions. G10 itself is only slightly heavier than FRN. But several new Spyderco models use steel liners in the FRN versions. My Endura 4 is very close in weight to my G10 Cara Cara, and they are of almost identical size. (I think the slightly wider blade profile of the Endura 4 accounts for part of this).
It's funny though, I have no problem with FRN guns. I like my FRN Glock, Beretta and Walthers just fine. I bet I'd like them even more if they could somehow make them out of G10.