Got my bluray and watched it last night, and holy crap! The sound was ridiculous! The dynamics were off the chart, great bass, overall it was almost overwhelming. It was the first time I've ever turned the volume down from 0.
BTW, I'm using an Onkyo 805 receiver, outboard D-Sonic Magnum 1000S amps for all channels (3000 watts total), big (and incredibly dynamic) speakers all around, 4 AV15 subs run by a Crown K2 2500watt amp. 65 inch Mitsu Diamond 1080p DLP.
Iron-Man was impressive, but Hulk was an unreal experience! My cat normally sleeps on my lap for movies no matter how loud ... but last night he hid under the bed upsairs