The good: Ho-Oh GX is an inacredibly easy way to get Charizard GX into play.
The bad: who cares? the only merit of Charizard GX is its mill attack, and you can't use it anymore because you just used up your GX attack getting it onto the bench.
The ugly: on top of the fact the combo is self-defeating, the energy demands of such a combination are ridiculously unmanageable, to the point you can take the existence of Kiawe for granted and it's not that helpful.
Random thought: is SM4 going to be the Grass type's time to shine? In response to Aqua Patch and Kiawe, can anyone else anticipate that instead of just going down the Forest of Giant Plants route again, they release a Stadium that turns all Pokemon in play, each player's decks, and discard piles into Grass types?
I wonder if the official ruling of this card will allow putting [R] Mega Pokemon-EX from Discard Pile to Bench. Not that any [R] Megas are crucial players to the metagame anyway. But it would be nice to put Mega Charizard/Houndoom/Camerupt/Blaziken directly to the Bench.
As for [G] types, I think it's having a moment now. SM1 introduced Decidueye-GX and Lurantis-GX, then SM2 with Golisopod and SM2+(Promo) Lurantis. All that while Forest of the Giant Plants, Revitalizer, and item lock Vileplume are still part of Standard. Personally I'm a fan of Grass decks, too, but I'd like to see more Grass support Trainer cards later after the rotation. Would love to see a viable stage 2 starter GX, maybe Venusaur or Meganium? With the first attack with 1 [G] or DCE Energy cost, please!