gunit2004,
I toyed with 12 and 12.5 and ended up sticking at 12.5 because I felt like I could still move super slowly and not register the smallest movement. I might try 12 again after you did. I think the key (be it 8 or 12 or whatever) for anyone else is the exercise in increasing the bottom of the curve until it feels natural on their end.
I don't know enough about curves to know if mine which ends up back at the corner or yours/humanfemale's that stays straight until the top edge is the right way to go. I will have to experiment more. I don't want a deceleration. My thinking initially was that I wanted my full range of mouse movement at top speed. It was feeling to me that maybe your style of curve at the top end was translating full-mouse-input to slightly less than maximum turning. The way I was seeing it was on the bottom end of the curve, I want my tiny mouse movement (X axis, starting at 0) to actually translate to inputting 12.5% to the console (y axis starting at 12.5) so we can overcome their deadzone, which is why we raise it at the start of the curve.
And at the top end, I want my 100% mouse movement (x axis at 100) to translate to 100% input for the console (y axis at 100), so I put it all the way into the corner. What I worry about with your curve is that my 100% mouse movement is actually only sending 87.5% to the console. (100 - 12.5). My further reasoning was that as long as I'm drawing a straight line from my 12.5 in the start to the corner, it should feel natural, but maybe you're right, the 87.5% is fine and could be overcome with more sensitivity? I'm not sure. I am no curves expert, so I'm not positive this is what's happening, but it felt like I had the small control but that I wasn't able to turn as fast as I wanted until I changed that curve. But I'm interested in getting more info or experience with it.
If you don't mind experimenting between those two options at the high end, I'd love hear your thoughts on it. I will do the same when I get a chance.