Never saw LS, would have loved to, especially back in the day (first 3 albums).
I was a DH fan for their 1st 3 as well, after that they started to sound more and more like everyone else and getting softer. But The Triptych was awesome. If you have ever seen the live DVD that came with some copies of the Triptych, i was at that exact show. Woot.
Oh, Sleeper is not bad for metalcore. That style is so overdone and burned out though. It kind of took over, and it seems music has just stopped progressing from there. Normally a style takes over a few years, then another style progresses and takes over. This hasn't happened with metalcore and it really shows a style that has been stretched beyond its limits.