I don't know, but Buy + SY EP = Tons of Fun
Edit: After going back and listening to them, I can see the resemblance. It has something to do with the basslines - both are simple repeating patterns. SY's a little more simple. And both songs have similar guitar sounds. I'm not a guitarist, but it sounds like they're bending notes to create sort of really loose glissando sounds, maybe with a tremolo arm? Also, both songs have screaming declamations as vocals.
It's hard to pick which song I like better. SY has better drumming, better screaming/lyrics and more interplay between guitarists (of course). JC and the C's have the advantage of keyboards and saxophone and an actual guitar solo that's pretty cool. But, I'm going to go with Kill Yr Idols because it works better as an actual piece of music--it goes somewhere and comes back. There are dynamics and tempo changes and a much more kick-ass middle part. The end.