I'd like to add.
I've done some further experimenting on the subject and I find something very odd. If you press shift and scroll around the camera everything is nice and smooth at 60fps. But when you click for the character to move somewhere, then everything drops to 40fps, hence the "flickery" and clunky feeling when moving.
This seems to be hard-coded in the game so I doubt that there is a solution around it. Also stuff like this might not be even noticeable by most gamers, but a a 20fps difference is really huge for my eyes and that's why I've been obsessing so much over this.
I really love DD but the fps drop is really distracting me, even more now that I've seen how smooth the camera movement can be at 60fps.
First world gamer problems I guess