downsides to optical mice?

So I'm sick of using ball mice, and how easily they gum up even after you clean them.  i've been thinking of getting an optical mouse

do optical mice have any common problems of their own I should know about?

>>11
listen to this man.

i purchased a logitech MX and its no-fucking-better than the $10 opti mouse that came with the system in the first place.

all this 1600+dpi bullshit is just that, bullshit.