A lot of Nero's early concepts were way better than what they ended up with, IMO. That's the first I saw his DT though. Interesting. Just sorta shows you they had an entirely different idea for him at first.
I'm ok with Dante's DMC4 DT as far as looks go. That is to say, I don't really like any of them all that much. But to quote the professor "I've grown accustomed to [his DT] face" in 4. So, if they change the appearance up I won't be upset, but if they don't, I'm fine with that too.
Though, if I were to have my silly little way, I'd overhaul the look completely for something more "Tiefling" look (a la NeverWinter Nights), complete with the stylish arrowhead tail and the handsome set of horns. :lol: I guess I prefer the subtle, if stereotypical demon-half look they had.
As for Nero. I.... don't really care so much what they do with him. But if I were to manage an opinion of his DT in 4, it was kinda gimmicky. But I thought his DB nightlight hand was too. As well as his fancy fire sword. So, I guess it fits him.
Seeing that concept art (along with his regular early designs) really makes me wonder what I'd think of him if they'd kept the original idea intact. But that's another topic altogether.