Odd, I find P2s mouse control with a virtual stick essentially to be the most unusable.
To me WCP had the best (which was certainly close to Freelancer). In real terms they're the same (minus the inversion) but the mouse pointer is a lot easier to keep track of than the little mini sliders in P2.
I'm not really a mouse person but I can happily play WCP with the mouse, not so for the rest of the titles (but especially P2).
But the bouncier physics in P2 I do prefer, there's no momentum in WC4, the game seems to deal in 1d speed rather than 3d velocities (something I rant about in one of the updates on the remaster, for some reason the WC3 3DO port doesn't have this issue).