1) When going through the guides, the line has a hissing sound just like a pissed-off cat. I am not sure I could get over it.
2) The texture of the line feels harsh at times. I tore up my hand on a smooth line fishing for a week in Baja. I would hate to think what this line would do to me. Stripping glove are probably a must when using it.
3) This comment is pure speculation, but I worry that the textured line could pick up dirt and grime. My lines got filthy this summer when fishing for bass. I could imagine that the Sharkskin could be worse.
4) The $100 price tag. While the fly line and fly rod are the most important pieces of gear in your arsenal (besides a good attitude), this seems a bit excessive. The top end Rio line is $64.95