I love the fact that they turned around so soon after SRNR.
I like the idea of a punk album.
HOWEVER: I just don't like the song itself. All the members of fall out boy are very talented at what they do and this all feels a little TOO simple for them. By adopting this "punk" approach they immerse themselves to much in the "punk" style and lose the "fall out boy" style that made them so special. This just sounds like a lame track from Green Day's Uno with Patrick singing.
I think part of the point of this release is re-asserting that they don't have a sound and they don't have a genre. This is some stuff they threw together in 2 days for fun with a guy who doesn't have a genre either, so it's going to be interesting in a napkin sketch way rather than an oil painting way.
FOB has never released quick takes or anything from this sub-style of punk before and that alone makes it pretty exciting for me. Now that they've done it, they'll probably never do it again -- at least not quite like this.