DMC 2 is better than the first one. There, I said it. It's in-between DMC 1 and 3 in terms of controls, animation and how the game works.
I completely disagree. I went back and put in the 2nd game on a whim thinking, "Maybe it's not as bad as I remember." Well it was worse than I remembered. It's muddy, ugly, way too easy (not even by DMC standards, it's just an easy game), the environments are indistinguishable hallways or indistinguishable city-scapes. The only good things were character and enemy designs. Dante looks the coolest in 2 and the skeletons look cool as well. Infected tanks, on the other hand, look really bad. Anyway, just my opinion.
On topic: yes the first game is really hard to go back to. 3 and 4 are really fun, but the first is good only if you have nostalgia for it.