I had sumitomo's on first they are very nice, it was funny that this thread came up because my friend and i where talking about this yesterday. But the spec2's have crushed hazelnuts and walnuts in there compound, almost to the point of sand size, so you cant even notice, they are better in wet conditions, when you need a little bit more traction. The reason for the hazelnuts are because they never break in a rounded fashion, they always break jagged. I heard they are a great tire, but i really loved the sumitumo's, they look nice too.