I really like the Wac'em bhs, i am replacing them with the shuttle T locks. They T's fly even better, but unknown takedown performance. I smoked my buck last year with the Wac'em and got a clean pass through from 32 yds, the buck only went about 35-40 yds after the shot.
I'm surprised there isn't more than 2 pages of responses so far! Seems like the head choice discussion is the one debate that will go on and on. Like asking a rifleman which caliber is the best.
I loved using the ST Standards last year, with no rattle at all. Like some others said, contact ST and let them know what the problem is. I'd be shocked if they didn't swap them all out for you.