To be honest, I absolutely hate touchpad anything. I'd much prefer tactile buttons over touchpad. The UI of the cowon takes quite a while to get used to, and I still haven't figured out everything. That being said, I'm well on my way to being accustomed to it. Plus the tactile volume buttons can be reconfigured to skip/rewind tracks in hold mode which is a beautiful touch.
Oh and touchpad sensitivity can be changed, from 0-4.