I think its kind of like when Pokemon TCG changed to the newer sets. Like for example in the old set, theres Trainer cards and you could play as many as you wanted, but when they switched over, and had Trainer Supporter cards, you could only play 1 a turn. Much like how GI is with the Power Level.
Ugh, stupid Supporter cards, costed me that one match in the finals.... Whatever. Seeing as the new cards have ridictlous new bonus and everything, well see about that. But the Bakugan, everything is way up there.