Sound — 10
Firstly, after listening to Fear of the Dark (haven't listened to the middle albums), the sound I expected would include keyboards and over the top progressive-style music. I was pleasantly surprised when I heard a clash of the 5 instrumentalists in action and felt a core sound that was similar to their live sound from the Somewhere Back in Time tour shown in Flight 666. Bruce's vocals are excellent for both his age and in general, and the chorus comes alive in this sense. The solos are all addicting, fast, and ran through my head the entire day. The bridge is also a archetypal Maiden build-up and thoroughly fits in the middle of the song.
Lyrics — 8
The lyrics are clever and unique this time, and were based on a Spanish myth as an allusion to a probably greater moral or message. The feel brought out by the lyrics was much quirkier, though less remarkable than anything from Number of the Beast through Powerslave, my personal golden age of Maiden. Maiden is definitely back to stay, but I haven't found it in me to shout these words out while I hear it.
Overall Impression — 9
Out of every album I've heard in the past two years, this is definitely what rock should be. Iron Maiden placed their best riffs into one quick and energetic song to boost their come-back after 3 years or so, and this song is definitely worth the download. It's free on their site too, so there is NO reason to not experience El Dorado.