I'm so glad that the Metal resistance came back with the new generation. I hope, they make another (playable) Ampharos (and they have to, because of existence of Mega Ampharos), although not in this set. It'd be great and I'd be very pleased, if they bring back some strong fire-types other then starters, and more importantly without wasting energies - something like Rapidash or fire version of Houndoom.
On another note: I really like the FA's I saw, especially Venusaur and Blastoise, cool! 10/10.
My opinion on some of the trainers:
Evolutionary soda = hyper strong card, because it isn't supporter. Good chance to get the evolution back to the game, maybe.
Professor's letter = deck-searching version of energy retrieval; cool, that it isn't supporter, too. It's a station between E. search and Cilan.
Red Card = reincarnation of Imposter Oak's Revenge from oldest Team Rocket; cool thing, it isn't supporter, yay! Maybe OP (It's a stronger or weaker Judge)
Super Potion = fine, although I dislike trainers that requiers discrading your own energies from Pokémon. A more healthy Pokémon is stronger, not weaker, so it's contraproductive to heal it and "discharge" at the same time (especially on expensive attacker).
Punk Guy = I can imagine decks that use its strategy. It'd be even more powerful, when it shuffles your opponent's beast
Heavy Charm = eviolite for all stages of a Pokémon, good card.
I can't wait for rets of the cards…