It's lost crush attack is ok-ish, but it's not very realiable. It's breakdown attack is one of those attacks that the opponent can manipulate quite easily, although it can get around Rescue energy and Gengar's Fainting Spell, but in the end Mismagius GL lvX > Banette TM in this case, as Mismagius GL lvX only cares about how many cards are in YOUR hand (though it only maxes out at 8 damage counters) plus it can use the SP engine.
Even for league play this card is quite iffy especailly with its 2 mediorce attacks and low HP even Masquerain SV would be a better league deck than Banette TM.