I play a solid 10, it dont really count though cuz im actually a call of duty player and i play 10 in cod. if you scale everything down and what not a 10 in halo is about a 2 in cod so i like being able to shoot people before they are even physically able to get the reticule on me, let alone aim.
I move around a LOT. Infection: 10 FTW! BTB: 4 Snipers: 3 (5 if Shotty Snipes) CTF: 6 Swords: 8 ... I just realized how flexible I am with Sensitivity.
I went on vacation, didn't play halo for about a week, and my sensitivity has decreased from an 8 to a 5.
I played at sensitivity three for the longest time, but for some reason I stopped playing Halo for a little bit, which ended up in me decreasing it down to two. In which I've been at two for several months now.
Actually, I find one to be the best for standard Slayer, and for Swat i prefer two. I sometimes jump up to three but i dont really like that to much..
For Campaign: 4. Auto-targeting gets annoying. For everything besides Grifball: 8. And 10 for Grifball.
10 for everything, even though I ocassionally miss shots beacuse of it. Though after playing CoD on 10 for a while, it still feels slow.
I just play on the one it starts out with i don't see any point in changing it when you've used it in every halo game