I played the 100w at Guitar Center Platinum room and it sucked. Maybe their QC sucks as the amp I played through sounded decent but I had the volume at 1:00 and it wasn't that loud at all. I turned it up to almost 2-3:00 and it was still not super loud. It was in 100w mode too.
By comparison I played the Shiva with channel volumes around 12:00 and the master on 9:00 - 10:00 and it was crushing.