I'm paraphrasing, but does this sound familiar to anyone?
I don't know the original source, but there's a page with quotes from Maiden members on all their albums.
http://teamrock.com/feature/2015-09-04/iron-maiden-album-by-album-in-their-own-words Re: SSOASS, Steve is quoted as saying, “It was a new challenge for us, making a concept album. I’ve always loved prog – Yes, Genesis, ELP – and this album’s title track was a powerful song with
that prog element to it. Not everyone liked the album at the time. Bruce even said to me that Queensryche had made a better concept album that ours, with
Operation: Mindcrime. I said, ‘That’s a really good album, but ours is a fucking great album!’ "
I'm with Bruce on this one.
Seventh Son was overall a disappointment for me, though there are still a handful of tracks off it that I like.
Mindcrime was more of a coherent concept, and the songs were more consistently good -- not really a clunker on the whole album, but
Seventh Son had a few.
Maiden also showed a lot of respect for Queensryche in the mid-late 80s, which I'm sure the guys in QR were honored by. Harris and Murray both praised them in interviews as one of the newer bands that they enjoy, and you can Google Image Search several photos of 'Arry wearing different Queensryche T-shirts back in the day.
A few months ago I listened to an old radio interview with Maiden from around the time Live After Death came out. The interview was interspersed with musical clips from the album (edited out of the MP3 that I found, and sorry I don't remember where I found it or I'd link it). But towards the end, the host played "Warning" by Queensryche, and said that they were playing that clip at Maiden's special request.