You think if shimano parts had the direct cable routing they would work the same/better/worse? Now why can't you use a X.x derailer with a Shimano shifter? If you can setup a 8sp and a 9sp, the 1:1 would go out the window right? If the shifter is the piece making the 1:2/1:1 ratio, whats stopping you? Would the X.x derailer shifting be reversed, if used with a shimano shifter (forefinger to goto larger cog, thumb to smaller)?