DNA said:QFTPersonally, I'm not a fan of modified at all, and I haven't been active in league play lately because I haven't found any leagues in the area with a good number of unlimited players. (Yes, I can often beat modified decks with my unlimited one, but what's the point?)
That said, I wish there was some kind of middle ground. Banning a few broken cards or combos (I haven't personally played against the Aero/Dark Vileplume/Aggron EX deck, for instance, but it does sound fairly unbeatable if the deck isn't designed to counter it - then again, modified is often dominated by a few decks as well) without throwing out 80% of cards ever made.
My friend brought an Unlimited deck to League just for fun once, and it was basically a donk-style deck using Porygon-Z's Overload, combined with a bunch of Item Finders/Seekers/draw cards to get rid of the opponent's entire bench (the deck can use Seeker 6+ times in one turn very easily via Porygon2's Download) and then Overload for a KO.
And people wonder why P!P does rotations. I don't understand the people that don't get why; I really don't =P
I'm not convinced that deck's unbeatable. For instance, there's a card in unlimited called focus band, which depends on a coin flip, but if it flips heads the would-be-KO'd pokemon survives with 10 HP. Easy to throw into any deck and gives you a chance against that donkfest, so if it became an archetype I'd throw some in. Next turn you can bench all your pokemon again. and your opponent will probably be pretty vulnerable - you'll have a full bench and they'll have a huge discard. Then there are staples -goop gas attack slows down any deck dependent on pokemon powers, Aerodactyl evo-locks them if you get 'em out fast enough, and Dark Vileplume decks stop it in its tracks if they're faster.
EDIT: Forgot about windstorm. Maybe *that's* not the counter after all.
That said, a ban list would not be a bad idea. Because I hate having a couple decks dominate the metagame in modified, and I wouldn't want to see it in unlimited either. If, y'know, enough people played that we could speak of a metagame.