I used to, when I had everything set up in my big basement, have 500W per channel (2 duplicates of Mark Levinson amps, I really miss them) of on my front mains, and 200W (Carver M400a) on my rear surrounds. I had 300W (Crown) amp on my sub, and it was barely enough on some soundtracks. If the sub hadn't died when the pipe broke in the basement, I would have upgraded that amp for sure. I lost my Ar-9a's, my levinson clone amps, the sub, and several components when they got soaked. Depending on the speakers I had, I sometimes would, if the meters were even close, be pulling 400+ watts on the mains on some movie soundtracks. Judging from the way the lights dimmed, I would bet the meters were pretty close. If my friend who built them was still alive, I would have had him rebuild the 2 Levinson clones, and make a third one to run the sub. He loved "cloning" really expensive amps.
I got a nice chunk of money for the aluminum scrap when I took the Levinson clone cases to the local scrap place, almost 25 pounds each! They were huge 1/4" plates welded together. Had a nice silver "industrial" look to them.