I agree, Pumpkin. Not every power metal band plays it by the numbers. If that were the case, we wouldn't have bands like Jag Panzer, Angel Dust, Steel Prophet, Blind Guardian, Rage, Tad Morose, Savatage, and Brainstorm. However, I do believe that Ark is a progressive metal band. Their music transcends several boundaries and serves as a showcase for the technical prowess of its members. Only the cream of the crop can can do both with their music, whereas most bands lumped into the genre only do one or the other. If you're looking for reccommendations, I would highly suggest you check out Attention Deficit, Clockwork, Destiny Dreaming, and Freak Kitchen. I believe all of these bands, like Ark, were/are doing their own thing while tearing it up on their instruments.
Stay metal. Never rust.
Met-Al