In looking at both the Textured and the Sharkskin finishes it appears to me that the Sharkskin would have less surface area touching the blank and guides and so would have less friction for longer and easier casting. I can't say for sure but it appears to me that indents like the Textured lines would catch and trap more dirt that the Sharkskin.
Having used Sharkskin almost exclusively on 4 and 5 weight rods I can say that even after a hard days fishing and stripping line with them that as long as you vary where you strip the line across your fingers you will draw no blood by the end of the day. If you always draw the line across the tender crease inside of your finger joint you are looking for trouble even with smooth lines if algae or salt is present.
Besides. The 'Skin costs more so it must be better!