Rev was fun I aint denying that. But he only had a certain amount of moves. It was much easier to get stylish ranks as Dante. Dante simply had more options, A LOT of more options in fact. Just playing around with Dante's starting equipment and all his styles he already had a more varied moveset. Not all of them were combo related but still. Nero may have received some DT exclusive moves but most of Dante's moves were altered in DT, Stinger for example was AMAZING when DT'ed. Like I said Dante just had more options and felt more fleshed out and Nero seems limited in comparison. Same can be said of DmC Dante. He may not have rev or buster but he took the grapple mechanic AND obtained multiple weapons giving him access to many more combos than just Nero's 3 ground combos and 2 air combos, not to mention delay inputs can be applied to other weapons in mid combo giving DmC Dante even MORE variation. (still doesn't compare to DMC4 Dante's style system though.)
Was Nero fun? For the time yes. But now with DmC Dante I have no desire to see a character with a grapple system yet only two weapons. The rev system is all Nero has going for him now.
Ironically though if we gave Nero more weapons he'd probably play similar to DmC Dante plus a rev system. --- When coincidence is so convenient, I prefer to call it fate.