Honestly, I love GTS..when you're searching for a Pokemon you need to just fill up your Pokedex. Other than that, the way it's setup is horrible. You can't check the Pokemon you wants IV's or stats as they are now. The worst things are these:
(1)People asking for Pokemon you can only obtain once in the game(Mewtwo, Yveltal, etc) for a Charmander or an Aron. Now listen up, I'm not gonna trade you my Mewtwo for your level 1 Charmander. You "say" it has 6 IV's, but when I get it and find it has none, I will throw my 3DS against a wall. So I refrain from ever conducting those kinds of trades.
(2) People asking for Pokemon that CANNOT be obtained in the game and/or Friend Safaris. There are over 700 Pokemon, yet you choose one of the few that are no obtainable in game whatsoever?(I see EVERYONE asking for Mudkips..). I get it, you want those Pokemon, but NO one will have them until the banks come out a little bit later, so for now, please ask for Pokemon that people can actually give you...
Those people are not looking to trade theyre looking to show off what they got, which is stupid because no one cares, but that's the general idea.
Typically if you make a regular pokemon available for trade that isnt overly common and ask for something else that isn't a one of pokemon youll get the trade within minutes. Legendary for Legendary probably works the same way but havent tested this hypothesis yet
Pokemon Black FC = 3396 8733 5419 3DS Friend Code = 5155 - 3829 - 9448