Actualy, having listened to both albums recently in their entirety (yard work - it helped), I could absolutely see Amaranthe being a bigger hit in Miami than in central FL. It's their poppy/Industrial crossover style. Crank up "Electroheart" and you'd get scantily clad tanned Miami bunnies bopping all over the place, on the bartop, on top of stools, hanging from rafters - all with neon citrus colored lights swirling all over the place.
Amaranthe has that "Miami Sound Machine" vibe going that could actually get people in a club - if there was proper marketing in that area. South Florida has a completely different dynamic than Chicagoland or the Atlantic Northeast. It is also hella out of the way, and once you go to Miami - you have to turn around... or go to Cuba. Probably explains why no dates there.
I just sent Electroheart to a guy who I know here and works as a club DJ. I asked him for an awesome techno/electro mix for the song Electroheart (as if it really needed more), as I agree with you 100% that this song could do very well in a nightclub (if given a little "treatment").
Looking forward to the result.