EX Dragon contains powerful Dragon-type Pokémon. In the Pokémon TCG, most of the dragons are Colorless-type Pokémon. At the moment, no Pokémon has Resistance to Colorless-type attacks. Furthermore, most dragons have two Resistances and lots of Hit Points, and their attacks inflict large amounts of damage. Because of these advantages, it certainly wouldn't hurt to experiment with dragons in your decks.
Here's an example of one of the dragons: the Dragonite ex (90/97) is a Colorless-type Pokémon-ex. It has 150 Hit Points and Resistance to both Fighting-type and Grass-type Pokémon. It can move Water or Lightning Energy from its teammates to itself with its Call to Power Poké-Power. Its Dragon Wave attack can cause 70 damage if you discard one Water Energy and one Lightning Energy, and its Giant Tail attack can cause a whopping 120 damage if you flip a coin and you get heads. Scary, huh?