Attack's have VERY aggressive nurls... I've heard that they may tear up the soles of your boots if you're riding on the street. Those can be changed out to be either shift pattern apparently.
I've got Vortex on my race bike (R6) and like them a lot, not sure if they're out for the S1, thought they were though
On my S1 I went w/the Gilles. Those have been great, plenty of grip IMO and plenty of adjustability. They make great stuff.