Mouse before mousemat anyday really. I do't even use a mousemat and i've got a mouse that costed me ike... 15 but if I would make myself spend tons of money that otherwise can be spend on alcoholic baverages I would certainly get a mouse over a mat, i have some friends who play SCII hardcore, they've got mechanic keyboards and mouses and all that bullcrap and I must say it does make a difference but it only makes that difference if you buy a mouse of 80+ bucks, comparing a 15 mouse with a 40 mouse I don't feel the difference only the high end mouses have a noticeable difference.
The clicking is so smooth..