Well I can't judge a game by its box art (does that ring a bell?)...
When further details on the legendaries & their types are revealed maybe then I'll decide which version to get, or maybe I'll just choose based upon version exclusive pokes?
Anyway I like both designs, you people may hate the X one cuz it has a blank space but actually it doesn't, it's probably a shade of blue (maybe cyan?) but as there is a bad flash effect we see it as white.
Again, wait for the REAL box arts before you judge.