I too have sensitivity problems.
My windows 1.1 sensitivity is 17/18. My gpp sensitivity is around 25. Cl_mouseaccel is 1.
On my mac, cl_mouseaccel is -1 for reasons i won't say here, read below. It kinda seems the same as cl-mouseaccel 1 on windows.
My sensitivity on 1.1 mac is 38. [not high enough somewhat]
Gpp is 110. WTF. Yes. 110. When i'm sniping, i need to move around to shoot those parts where i cannot shoot, because movement in aiming is very squarish. If i twirl my mouse in a circle and shoot with a lasgun or pulse rifle, you'll see a pixelated circle of somewhat on a wall.
Also, how do people play with a sensitivity of 1.5? That's crazy.
The macintosh aiming speed: If you increase it, it doesn't increase the movement speed. Instead it adds to the mouse acceleration in squarish amounts.
[For example, you get a weak mouse, and put the sensitivity on highest on the mac, you move the mouse a little, it moves a little. No biggie. If you move it slightly faster, it goes 3x faster. Move slightly faster, it goes 9x faster. WTF. And there's no intervals between those multipliers which is why i say it is 'squarish'.] This is why i complain about how much macs suck. And i'm stuck with one until i get my own windows computer or get my OpenGL working on my virtual/bootcamp windows.