It's just so sonically complex, ALL the songs, and that's saying something for U2.
I have to listen to it again, in order, with Vertigo in place. Still, I like it a lot. My favorite so far is OOTS, but MD, ABOY, and OSC are up there too. The other tracks have more vaporous melodies, so they don't "grab" you at first like the others do. That's fine, though... I wouldn't want U2 to make an album of just cookie-cutter hook-line-and-sinker rock tunes. There's gotta be depth.
Only criticism so far is that some verses on some tracks, i.e. COBL and Yahweh, are "delivered" rather than "sung."