This album really is one of the all-time classics of heavy metal. I was dubious about the concept-album thing as a dedicated Metallica/Anthrax/Testament listener in the very early nineties, but this album changed my views. The emotions wrapped up in every song, the soaring, screaming guitars.. If you like heavy metal, you owe yourself this album!
That said, I still like Metallica, Anthrax, and Testament, and if you can't handle slower hair-metal, this album may be difficult for you to handle. It's definitely an earlier breed of metal, focusing on actual musical skill - Jon Oliva has a great singing voice (no incoherent bellowing in this album), Criss Oliva is an incredible guitarist who impressed even the best guitar players I've known.. This album is a class package, and every old-school metalhead I've hung out with respects it.
(I will admit if you're only a nu-metal bod, you may find this album rather disorienting. Power chords are not the driving force of this album. Go on though, TRY it!)