Whats a good sensitivity?

I just have had mine on default sensitivity and do somewhat fine but i want to improve my speed is there a better sensitivity for a regular sniper?

Low is better. I keep mine on 3 for sniper, 7 on any other class (does take a little while to get used to it, but overall I feel its better). However, basically, its whatever you feel most comfortable with, and are most used to. I have been using 3 for sniper for so long, that if I change it I can't hit practically anything. Also, keep in mind there are other factors to mouse sensitivity rather than just the in-game settings.

i set my mouses dpi to it's highest and crank up the regular windows sensitivity, with the game sensitivity settings default or lower you should get really smooth mouse movement and crank out the headshots.

I leave game settings at default, and bump up my mouse dpi.  Took me a while to tune it, but I've finally dialed in settings that are quick but comfortable for all classes.  The game automatically dials down your sensitivity when you scope in (I think it's even configurable how much), so there's no need to switch when sniping imo.

I would think its more dependent on personal preference than anything. I mean, if you can snipe with high sensitivity, more power to you. I prefer low sensitivity myself, and I didn't really change my sensitivity by class.

For sniping mouse DPI all the way as low as it will go (mine is 400)
and i use a 2.9 sense in game.

http://www.teamfortress2fort.com/forums/t/ImprovingYourAim-12939.aspx

thanks a lot, i never knew you could change the zoomed sensitivity like that.