Actually the stock grips weren't aggressive enough. The material I covered them with is commonly called 'Skate Board Tape" and is kind of like sandpaper, very coarse grit sand paper.
If you take a look at the tactical 9mm XD you will notice the grip has been sanded down and recontoured, stippled and then resealed with exopy.
Same basic thing, just a different way of getting to the same place. I like a very aggressive surface on the grips of my pistols.