Act II takes a lot to sink in, I think it's more complex and a lot more deeper than Act III, and generally their best album. I'm not sure if it's just me, but Act III seemed more poppy and mainstream (kind of like Coheed and Cambria's 'No World For Tomorrow'), but incredibly catchy!
I can't find these albums anywhere in the UK, had to import from US. It shames me that such an amazing band becomes a ghost amongst the realms of Gaga and Minaj. Complete shambles!