While I feel both versions have their appeal, I feel Nick's Jazz looks more like a Jackrabbit. I'm given the impression that he actually studied jackrabbits for reference. Dean's jazz is great, but I feel his Jazz is based on rabbits, not hares. Given that hares and rabbits are two different species, I like to play around with the idea that Dean and Nick's versions of Jazz are two different bunnies.

Hares are beautifully fugly (Looks more like Nick's Jazz)


Rabbits are cute and squishy. (Looks more like Dean's)



The following are traits that hares exhibit that we've come to love in the Jazz franchise...

Humor



Battle Mode


Special Moves


Pallet Swapping


Fun


And whatever this is... *EDIT* Power ups. This is definitely power ups.