I do enjoy the ITP holeshots that we have on our Z400 That is probably what I will go with if Les Schwabs carries them so I can put them on my account and pay them off slowly-ish.

Also on the LTZ we use ITP sand starts and I'm not too impressed with them to be honest, They work well but it just seams to be a little squirely at times.

One tire that Schwabs is trying to push is the GBC xREX which just like you said about the fast trackers they are a hard tire, great life span but I think I would have problems finding traction with them.