I noticed yesterday that there's some Yamamoto branded fluorocarbon fishing line available, in both a clear and gray color. It isn't anything new, but I didn't find any threads while searching for opinions. 

 

Has anyone used this stuff? It looks a little expensive, and the only review I could even find was one on TackleTour.

I tried the 12lb about 5-6 years ago.  I recall it was extremely expensive and just OK.  It kind of reminded me of  copolymer Pline  C21 and CXX, sort stiff but stretchy (I know that sounds backwards).  There are several other lines I like way better than this one (Invizx, Tatsu, Sunline Shooter and Trielene FC).