I think Nero's gameplay has a sense of purity about it; there are a limited number of tools at your disposal, but each one has a depth and utility which give combat scenarios flexibility and excitement.
Dante is more dog-gone crazy, and is still VERY fun, but as posters above have stated, Nero's gameplay is reminiscent of the uncluttered DMC1 gameplay which I so adore.
While I never want to see Dante gone, I really hope Nero's gameplay mechanics are the future standard for the series. Devil May Cry 4 brings it back to DMC1 quality for me, even though DMC3 was in its own right a very good game.
I must say, though, that the music of DMC1 has never been bettered in the series. Do any of the tracks in DMC4 compare to the Nelo Angelo battle theme? If i'm not mistaken, the Angelo Credo fight sounds a little familiar at some points, but hey, could just be me.
Speaking of Angelo Credo, BEST BOSS BATTLE since Nelo Angelo, IMO. has that awesome one-on-one feeling, great setting, great character design, tough, but not ridiculous (like Dante), just great stuff. BUT HOW IRONIC IS IT that he is the only boss that YOU FIGHT ONCE.
Lol, it's the only battle I would have liked repeated