Yay, a thread about the deck I've played for so long. ^^
Banette was always different, even from other T2 decks. You could easily run techs in other T2 decks without ruining them, but not that many in Banette. Since you want to T1 Ascend every single game, as it's one of the best basic attacks there is for a non-starter (ie, something that can evolve in something that attacks)
... *cliffhanger*
Until recently. Now that we have Phione (and, a bit less important here, Call Energy), every single stage 1 Poke is possibly a T2 Poke, as long as its Basic lies on the Bench with the little legendary water muffin (seriously, what is it supposed to be?!) Active. This even allows for stage 2s to be as fast as stage 1s used to be, even without the help of Candies in some occasions (little deck space or whatever). Sure, they won't be attacking T2; the Wish fish still needs to be sacrificed or retreated first. But attacking T2 is dead anyway because of Pachi, which has a full bench on T2.
So where is Banette now? Same place it always was: the fast G&G counter. But G&G won't be the best deck around for long, and Banette can't be the best T2 deck anymore after Worlds. Why? Because it's not a stand-alone Spitefully Paining machine anymore without Shuppet CG and will just have to rely on Celio's and Phiones like every other T2 beast. And its main prey will be gone to a certain extent. Also, Ghost Head donking is not going to work anymore in this very support-crowded format.
As for DRE, I've only ever teched in one in my T2 Banette and never had much use for it. If anything, it doesn't add very much speed.