It is an excellent record. I had it on cassette initially and completely wore out side A, at least until Suite Sister Mary, which I only listened to if I was listening to the entire tape. Spreading the Disease was probably my favorite, although I liked everything else except SSM (I think it was Pamela Moore's voice that turned me off). At the time, I mostly only listened to I Don't Believe in Love and Eyes of A Stranger on side B, but the deep cuts grew on me as I got older.
It's interesting that the guys in Maiden said they thought that Seventh Son was good, but that Mindcrime blew it away. I didn't get into Maiden yet for another few years, because No Fear for the Dying was out at the time, which wasn't the most representative introduction to them. I did get into Seventh Son (and all of Maiden's discography) by the late nineties, and would have to say that Seventh Son is close. Scenes From A Memory is still the best concept album, in my opinion.