tsk, tsk.
edit:
I suspect that Infinite Dreams
is a very difficult song to play and sing well, live, just as SSOASS (the title track) is. On this video (which comes from the in 1989 released VHS called "Maiden England") you can see and hear that Bruce has some difficulties.
However, his performance in the studio version comes close to perfection and (I can't stress this too often) these vocal melodies are really super, blending and interacting with the guitars, while Nicko and Steve show how strong the rhythm section is. As it turned out, Maiden never played it again, and instead they chose to do the easier songs (Madness, Evil & Clairvoyant -I am not saying they are easy to do, but I assume that they are easier than ID-), and recently they did Moonchild again, which was the biggest surprise of the last tour.
Powerslave, on the otherhand was played at 3 Maiden tours (one of them being the monstrous World Slavery Tour) and Bruce did it on the Accident of Birth & The Chemical Wedding Tour (with Adrian) and again on some festival dates in 2002 (without Adrian). So, no wonder that this song is played pretty well.
But to be honest, I try to focus on the studio songs. Why? I really dig some Maiden songs which they never did live (e.g. The Duellists or Only The Good Die Young) or hardly did (e.g. Infinite Dreams) and by checking live clips in relation to this poll I give less attention to these. Or the other way around: If I am going to focus on live stuff in relation to this poll I might be tempted to prefer those songs. Since this Survivor Game is about
all the songs I want to judge them in the same context, the only one possible: the studio versions.