I'm sorry, but all you're saying is that since Nero is more human than demon, that means he has more limits because he's a human, even though he has already shown some impressive feats for being a part of an actual demon. You can't dismiss this as Nero being weaker than DmC Dante.
It's like saying Zoro in One Piece has limits since he's a human so therefore he's weaker than Chopper (who is a deer that ate a Devil Fruit, giving him powers), even though Zoro is much stronger than Chopper to begin with.
*Incoming Technical Stuff*
Just judging by what we've seen during the cutscenes between both DMC4 and DmC, Nero could pretty much beat Dante.
At 1:02, Nero flings his sword around him in order to generate wind to clear all of the flames around him. That alone takes a lot of strength to do considering the fact that fire isn't easily put out by wind. Not to mention that it was a small town in which he took out the fire around him, not just from a single spot. And at 1:28, he blocks Berial's sword without so much of a struggle, with the tip of his own sword, which also generates a small gust of wind.
At 6:56, he literally swings Bael around like a rag doll. Afterwards, around 7:20, he punches Bael in the face, sending him flying in the air with very little effort. And lastly at 7:50, he rushed towards the hellgate and punches one of the frog demons in the face, which repels the rest of them backwards due to the force of the punch.
Further analyzing Nero's strength, OBD (OutskirtsBattleDome) lists Nero's physical striking strength around Class M.
Class M = (10^6 - 10^9 kg) or The mass of the largest ship, small pyramids.
Nero's speed is also placed as Supersonic+ since he is able to dodge bullets fairly easily. (dodged them when he was fighting Dante point blank with ease).
He can also fire sword blasts from Yamato in order to create large holes in fairly durable walls.
Now for Dante
Parts of the sections where Dante has to pull/destroy objects that gets in his way. As well as this, he has a pretty high tolerance for bullet fire since he doesn't seem to be injured by them even though he's taking direct hits.
Parts of the fight where Dante pulls the succubus several times while using Demon Pull.
20:02 specifically where he parries Hunter's lunging swing and tosses him to the other side of the hallway.
I'll be honest, these are the main videos where I can estimate Dante's true strength since he doesn't do much in terms of displaying his power during the cutscenes. At best, his strength level is just around large building level, if not that, probably around small building level.
Seeing how Dante fights like a brawler, his style mainly focuses on strength rather than anything else. And even though he's half angel/half demon, this doesn't take away the fact that he's still mortal, just like Nero. The only advantage that this Dante has is that he has low level regeneration in his base form. (which Nero has within his D.T. form) And even within Dante's D.T. form, it seems as if Mundus was only stopped for a brief amount of time before he pulled out his main eye within the boss fight. His D.T. is not nearly as potent as DMC3 Dante's Quicksilver.
And there's my reasons on why I think Nero can beat Dante. He's has far more destructive capabilities than Dante and he's faster than him. (I haven't seen DmC Dante move at bullet speed at all within any cutscenes. If there's cutscenes showing this, please correct me.) And again, this is just me judging from the cutscenes alone and not gameplay since mechanics can be kinda broken (RoyalGuarding for example).