I personally cant stand the ball mouses(mainly because you cant react with reflexs as fast, if at all), but if you can get used to the angles you have to make, then go for it.
The biggest thing about in CS in terms of hardware is all your preferance, because you do your best when your most comfortable.
i prefer one where i can move the mouse.. rather than just the ball.. tried playin with a mouse like that once.. couldnt kill a single person >_<
well I use a mouse with a ball... I've been using "ball" mice like forever so I'm like used to it I'm personally better with the ball mouse... but yeah everyone has their own preference
I have to say MX500 or 510 are the best on the market for cs play. They rock. If you have to go with any mouse and are will to spend 30-50 bux please purchase one of these. I converted from stock dell ballmouse over to MX500 and it took about 2-3 weeks to get use to but when I did it truly improved my play. I also purchased a funcpad 1030 and use rough side. THE PAD IS CLASS A FOR PICKING UP OPTICAL!