i've had HBWR + ecstasy at a few festivals, occasionally throwing some weed into the mix. Absolutely wonderful.
On that combo i peaked as infected mushroom came on, a few tokes and i was absolutely gone. thankfully i had some friends around to keep me out of trouble.
Deadmau5 was pretty damn epic too.
One thing about this combo is that i've found vasodilators/muscle relaxants necessary to feel safe. Magnesium and Taurine or Arginine work well for me. I usually head to the medical tent every few hours to get my blood pressure, pulse, etc checked, more out of paranoia than anything else, i've never felt unsafe/in danger on this combo.