I've identified and fixed what I once thought was 'static friction'.
Valve not only added non-linear options, but made the default setting to quadratic for episodes 1 and 2. Set joy_response_look and joy_response_move to 0 to set it to linear.
Although I haven't tried all of Valve games (only about 1/2 for now, need to save up for the rest) I'm confident that every single one has good 3dmouse support. It's a blast to play these games now, its so smooth!
, so it now sets the response to linear. I've also reduced the cl_ move speeds closer to the actual game speed caps, now that the response is linear. Let me know if any of the keyboard keys don't work, I haven't thoroughly checked them all.