While I agree that Rejuv is prettier/more lively and has a difficulty selector (though Intense shouldn't sell itself as harder than Reborn), I think that's about the only area it might win. And even Neo Reborn edges in on the pretty, though Rejuv has a solid lead still. Also, while the past two episodes of Reborn have stepped it up in sidequest department, Rejuv definitely blows Reborn away here. Those are really the only three advantages I see in Rejuv (though one is pretty minor).
The stories are very different, with Rejuv adding in a more supernatural aspect while Reborn tries to be as grounded in grittier reality as a Pokemon game can be. If Rejuv hadn't turned more serious later on, it might have worked in it's advantage to make it more distinct. This might change later (since it's still fairly early), but for now it feels like it tried to hard on the tragedy in some areas (which only brings up comparisons to Reborn in my mind). If it focuses on the mystery and supernatural elements more, it will become more distinct from Reborn again. The potential is certainly there.
Admittedly, judgment of the stories might be a bit subjective, depending on what elements you like in a story. Some people might not like more abundant supernatural elements in Rejuv while others will write Reborn off as complete edgefest.
Although the cast is certainly bigger in Rejuv, it doesn't mean better. While I'm ok with Melia, a good many of the other characters haven't been explored enough for me to care. Hell, literally two hours after finishing the episode I forgot the name of GDC trainer with the Flareon, who followed you around for half of GDC, just because I honestly didn't connect with his character enough to care; same with the psychic gym leader (Purple??). At least certain characters are either quirky enough (Saki) or developed enough (Venam and Alita) for me to really like them. Still, Rejuv is earlier on than Reborn, so some might just need time.
Edit: After reading your comment that you posted while I was finishing typing this:
"But he still has a better reason to go evil than Fern does! "
----It might just be me, but I really don't consider a Messiah complex that makes you turn to terrorists out of sheer jealousy to be better than Fern's general douchebaggery, @Jess
"Plus, Rejuvenation puzzles aren't as tiresome as Reborn's.
Plus Vivillon has 15 forms.
Plus Vivillon has 15 forms."
-----Fair points