I am looking at two of logitech's optical mice for my preciouuuuuuusssssss new iBook. I saw a logitech optical (plain, two buttons+wheel) that was white and silver for $18. I have a blue one on my pc and it works well. I also saw the MX310, which doesnt have too different of a shape and adds 3 more buttons. Does the MX optical engine make that big of a difference in gaming? How about graphic design? The extra buttons on the MX310 might be usefull. Anyone own both mice? Is the MX310 worth the extra $10?