I saw the show from the lawn of the DTE Energy Music Theatre in Clarkston, MI last night. 'Twas great.
Bleeding Through is a band firmly entrenched in the new mainstream metal style -- the same kinds of riffs, the same alternating screamo/singo vocals, the same invocations to the crowd to stand up and start a big ol' circle pit, the same shaved-head lead vocalist saying "fuck" every 10 seconds to convey how intense he is, etc. But for all that, they were all right. The best part was watching the female keyboardist windmill-headbanging while she played.
For Slayer a pretty sizeable pit formed right next to us on the lawn and went completely apeshit with about 50 people during songs like "Chemical Warfare" and "Raining Blood". Given that the lawn is on about a 30 degree incline, it was pretty wacky, with dudes getting knocked on their ass and rolling downhill every few seconds. So the pit was more fun to watch than the stage. I jumped in for about 60 seconds during "Mandatory Suicide," and that was enough for me.
Manson is as good a performer as advertised. Really interesting stage set variations involving projections on a screen behind the stage and various changing and moving props -- he performs from a giant chair for one song, and for another song stands on a platform that raises him up about 40 feet into the air, with huge jets of smoke pouring up from the bottom of the stage so that it looks as if he's actually levitating on the smoke... and of course the smoke/lightshow/confetti streams etc. make for a fun viewing experience. And besides all that, he does have some songs that seriously rock live (e.g., "Disposable Teens").
So it was a really fun show and my niece (whose first concert it was) had a blast.