Something I can't quite see in photos, and people don't mention in reviews - what is the button surface like on the Logitech MX Revolution? Is it smooth, or textured? I'm asking because I have sensitive fingertips, and currently use a Logitech MX518, which has a smooth button surface. I was sent a Logitech G5 once and had to stop using it after a while as the buttons have a rough, textured surface for grip during gaming (I suppose). I found the surface far too harsh on my fingertips. I don't need a completely shiny/gloss button surface, but just a "regular" one. How does the MX Revolution compare in this regard? It seems to be the best wireless mouse available, but I don't want to buy it only to find the surface too rough.