I thought Alucard's old voice fit his facial portrait much better. And with all the voices in that game, the extra reverb fit the rich, ostentatious look of the castle.
SO to me, the voices and the over the top lines just fit the rest of the presentation's package better. Whether the dialogue is more corny or not, I think most can say SotN's lines were much more memorable. SotN's lines were delivered like if in a play. It really set a fantastic theatric tone.
The only voice I really prefer more in DXC over SotN is Maria's, as it's higher-pitched and more youthful sounding. Considering her playful personality in RoB, I think this new voice projects that side of her past better.