This is way closer than most people would think. As Darkstorm said, it depends on where and which version. Btw, it's actually Nero Angelo, not Nelo. Nelo was a mistranslation, due to the japanese inability use L sounds. Someone assumed the R was a stand-in for an L, when Nero is the only thing that makes sense. Nelo doesn't mean anything. Whereas Nero means black. As in, the black knight, or as Nero's name translates: Black Angel.
I'm favoring Nero Angelo in this fight simply because he's alot faster and he's got the mobility advantage. Also, we're not using Night Terror, are we? Because that's an unfair match for any version of Nero.
The DMC3 SE take on Angelo?
Hmm, that makes it a little hard for me, since I know the 3rd apperance of Angelo in DMC 1 actually had more moves, a better teleport and black energy projectile 9The Phantom Blades don't really do much damage, even when used as a special...)
IMO, it depends really, Nero is fast on his regular slashes, but his real winner, Nero's take on the Stinger, is really very slow... His telepo rt dash may save him a bit of greif, but I wonder how many hit's he can take from Soul Edge...
Also, isn't his DMC3 incarnation limited by the amount of DT Vergil has left?