Yup, it's dated because of the cold war, but aside from this it is as good or better than any musical I have seen to date -- and I see a LOT! A review I wrote a while ago states it best:
Before we ever saw the musical, my wife and I fell in love with this beautiful original score. Full of passion and complexity, it makes the heart soar. Then, years later in England, we saw this original version on stage. SPECTACULAR!
Then, unfortunately, there's the American musical revamped version (audio is a red, white and blue cover) -- what is labeled The Broadway Cast recording. What an utter disappointment. Typically unchallenging and unpassionate. This seems to be what Americans want. I am an American, but can't stomach this mutilated version!!!
My advice: Stick to the beautiful original -- it is NOT just a concept album, it has been and continues to be performed in this breathtaking version (audio is a black cover with white chess squares) all over the world.