I like the idea behind cpudyn because as I understand it, its basically like the ondemand module, but a little bit less finicky, and a little bit more aggressive.
I'm trying to get my computer to be in performance mode the entire time I'm using it, and in powersave mode if I walk away. Right now it seems like its just jumping back and forth between the two while I'm typing this... that's not what I want. I increased the CPU_DOWN setting in /etc/default/cpudyn to 0.99, and it appears to be remaining in performance mode a little longer, and that's what I want. I've also reduced the CPU_UP to 0.2, so that it will enter performance mode faster.
After a few more tries, I ended up removing this tool. I couldn't get it to do what I wanted. Now I'm trying powernowd.