Eh, it truly depends on prefernce. Some people would like to OHKO a Uxie, right after their opponent dropped it. Others may want Empoleon to be alongside some disruptive Pokemon, like Omastar.
Which Empoleon you use is your choice. One isn't that much better (if at all) than the other, so it is OK if someone chooses to play one over the other.
Okay, forget I said anything. I was just mad that Infernape got Flare Blitz and Torterra got Leaf Storm & Wood Hammer while Empoleoon got nothing new and overpowered.
Even if the format becomes MD-on, what about the Empo Lv X from the tin? That's a black star promo, not a DP card. So wouldn't that mean he's still legal? Or how are black star promos handled in that regard?
I think when Upper Energy comes Empo will rise to the occasion, the only question is will that before the end of the this year's format? If it is this will be the first year since D/P that Empo doesn't get a World Championship Deck. Empo is a good tech and a possibility for Palkia G decks,, 1st you clog the bench and then late you can spread after Palkia G just destroyed everything. I am talking about the MD one by the way.