Lower. Here a comparison of both albums.
Piece Of Mind
Piece Of Mind was actually the first Maiden studio album I owned. I bought it at the same time with Somewhere in Time on CD. Up til then, I only owned Live After Death, the maxi-single of "Sanctuary" and the video "12 Wasted Years". Because of Live After Death, I knew 4 songs, of which "The Trooper" and "Die With Your Boots On" I liked the most. Especially "The Trooper" was one of my favourites of LAD.
When I played POM, I discovered that this album had a lot of variation! I liked all tracks! "Quest for Fire" isn't bad at all, it's actually very good! Maybe its lyrics are the silliest of the whole album, but to be honest, that doesn't matter for me. I really like the way Steve Harris changes his bass-playing in the harmony of the mid of this song.
"To Tame A Land" was my favourite. I didn't understand anything of the lyrics but it really didn't prevent me from liking it. Nice Arabic melodies, an addition in metal that I didn't know yet. The collaboration and interaction in this song (right before the fast part) is pretty cool, when Steve and Dave play the melody together and on the other hand Adrian and Nicko hit the chords and drums together. A few months later I saw the film Dune by pure chance with a friend. All those names popped up in my head! What the f**k? From that moment on I started to infect others (or at least I tried) with Maiden's music, realizing that there was more than music alone.
About the sound. What strikes me most is how full the rhythm guitars sound on this album. From all the 80’s albums they might sound the fullest/loudest. Killers comes pretty close though. However, because of these loud guitars the bass is sometimes a bit in the background (especially when the guitar chords are open). The solos sound more clear than the ones on NOTB and Powerslave.
Last word is about "The Trooper". This the one song that never bores me. I like it as much as in the beginning. It's the ultimate Iron Maiden track, containing all the typical ingredients.
Powerslave
Powerslave has been my favourite album for a long time, just followed by SIT and SSOASS, but nowadays I slightly prefer SIT, and it still changes. I have to admit that the high quality level on Powerslave is not the same from start to finish (“Flash of the Blade”, “Losfer Words” and “Back to the Village” are not my favourite Maiden tracks) but this album contains some of my favourite Maiden songs of all time: “Rime of the Ancient Mariner” (the absolute number one!), “Powerslave” (nr. 5), “Aces High” and “The Duellists” (nr. 9).
"The Duellists" is for me the ultimate "forgotten song" in Maiden’s catalogue. I find it very underrated and I can’t understand people when they say it’s boring. I like it because of the brilliant mid piece. GREAT melodic guitar work, with the rhythm tandem McBrain/Harris underneath it. The song has a catchy chorus, that stays in your head (not the way the chorus of TAATG stays in your head!). No weak parts. Unlike most Maiden songs, the tempo is all the time the same, but despite this, the song has an enormous drive!
On Powerslave we can hear a different way of guitar playing than on Piece of Mind. Adrian often plays different things than Dave. E.g. in “Rime…” and in “The Duellists” Adrian plays open long chords where Dave plays fast rhythm guitar (powerchords). For someone who likes to hear more variation and details in the guitar work, Powerslave is definitely the better “product”!
Realizing this, it's quite odd that this album features only two songs written by a guitarist (Adrian Smith)! It’s one of the very few albums without a Dave Murray-track on it. This album is especially a Steve and Bruce product.
The bass can be heard very well, and all sounds by Harris are clear to the ears, and the guitars are more separated to the side channels, compared with the full and fat guitars on the previous album.