Ayreon are one of those love 'em or hate 'em prog groups. Personally, I love 'em. No, I wouldn't call them progmetal like Dream Theater, outside of Universal Migrator Part II. But they do have some metalish moments. Most Ayreon releases are rock operas that are either an audiophile enthusiast's dream or an overproduced pretentious nightmare, depending on where you stand. If you're curious try either "The Human Equation" or "Into the Electric Castle". Both are double CDs and feature lots of guest artists. Lots of analog keyboards (organ, mellotron, moogs) as well as modern digital synths. If you don't like those albums, you probably won't like Ayreon.