WPM isn't entirely wrong to call Double Crisis kind of gimmicky. All we've seen, and are likely to see, are Aqua/Magma cards. There's nothing wrong with that but it does limit the uses for all of these cards unless one is willing to build a deck based just around Aqua and/or just based around Magma.
That being said Magma Great Ball is pretty good. The one thing I can't quiet tell, does it search for fire energy or fighting energy because either way that's a small limitation compared to the Pokemon that are part of Team Magma. I personally think it should give an option of fire OR fighting, but whatev. If Aqua ball does the same thing it will be pretty neat.
Well, if fire pokemon were to be included, you'd think Maxie's Hidden Ball Trick (kek) would allow you to target a fire or fighting type too. It seems that the PCL is adamant with having Magma cards deal with mainly Fighting-types (as very little sense that makes given the name..) My two cents.
It makes sense it searches for fighting energy since Team Magma are ground type team and ground is represented by fighting in the TCG. Though I suppose they did decide to go the fire route with Camerupt.