I like it, but I'm in the same boat as the 'why does he have a real weapon?!' crew.
I mean, Jaximus has one, too, sure, and I know the skins aren't exactly tied into the lore all the time (surfer Singed and, well, a crapload of other champ skins come to mind) but I mean, if they changed Diana's other skin because it didn't fit into the 'core ideal' of the character, shouldn't they keep Jax from having a real weapon as part of HIS core ideal?
It looks cool as hell, don't get me wrong. If I owned Jax I'd probably get it.