This seems to be the most common grip that advanced players use, but there are still plenty that don't. Eddie Van Halen doesn't use this type of grip. It took a bit to get used to, but I really like it now, and there are some distinct advantages to it.
Sgt Tee, yeah, I find the Lexan weird also. I saw an interview with Steve Vai that made me feel better, because he said the one thing he was really finicky about was his guitar pick... if he didn't have the right one, he just couldn't get used to it. So far, I'm just sticking with the Yellow Dunlops... its got the right feel for me, but like Fretsmith, I have a little dish filled with various picks... (and then a couple of packs of the yellow ones! :) ).