Hmmm
Well I think it all comes down to personal preference.
I've used a few optical mice, starting with the Intellimouse 1.0 (old school shape w/ optical and scroll), and more recently the newest revision of explorer.
Although great for general use, I still prefer my trusty Microsoft ergo 1.0 - again the old-school ergo shape, no scroll funtion, 'smoker's white' as I like to call it, and a big metal plate inside it that i've never seen before. Gives the mouse a fair bit more weight, which makes it easily the most accurate mouse i've ever used.
Dont get me wrong, I like the optical mice, but like some people prefer their 'boomslangs' and others no doubt have an 'old faithful' tucked away or possibly still in use.
I was, back in the day, a keyboard-only player (yeah well the mouse didn't really enhance doom or wolf3d ), so lack of buttons or scroll doesn't bother me - there's plenty of other keys around W,S,A, and D.
One thing's for sure - if I miss a shot in UT or TFC, i'm not going to go running out to get PS/2 port refresh rate improving software, or optical mice, or a big shiny metal ball that might someway improve my hand/eye co-ordination.
If you cant make a shot with a ball mouse then either it's a really bad mouse, or you need more practice.
If someone beats me, the first thing that comes into my mind is defintely not 'well his/her mouse must be better than mine...'