I ran that setup on my 350 race bike. You don't have to worry about sloppy shift linkages - no mis-shifts. All of my race bikes were setup with GP shift pattern. I sometimes have to catch myself in the middle of a down-shift while accelerating out of a corner
I remember racing 3 different bikes one weekend, all with different shift setups (GP pattern, street pattern and right shift) - talk about confusing
I'm thinking of switching my XS to GP pattern. It keeps your toes out of harms way when up-shifting out of a left-hander
It makes bump starts easy too - you can push in neutral and pop the bike down into 2nd gear while you land on the seat(side saddle).