I can argue either side of the question. First you have to consider the space your system will be placed in and the listening distance. If you have a soft room and a listening distance of 16 ft like I do, you will loose appox 10 to 12 db of output over the 1 meter rating. So with my speakers rated at 97 db 2 watts 4ft tri amped. Thats appox 85 db. So if I want 10 th or 12th row concert level of 105 db peaks, that means I need 200 watts. Well I seldom use over 70 watts combined or about 98 db peaks with a loud listening level of between 85 and 90 db. Now Paul Klipsch recommend for a front row experience you need 115 db peak levels, which would mean 127 db from my speakers which won't do that.
Mac speakers won't do that either. You need big Klipsch or JBL or some modified EV or Altec. Lets face it you would need almost 500 watts with Mac speakers to do what I do with 70 watts. And since 1200 watts is only 4.8 db higher it not out of reason. Oh my speakers are line array hybrids, and that 3db everytime you double the distance might be true in an anechoic chamber but not in a home. Once you reach the point where the Dc takes over the volume stays constant with in a DB or two while the direct sound of the speaker continues to drop and the reverberant sound takes over. Now as average folks listen around 85db with an occasional 10 db peak. I would only need 20 watts total and Mac speakers would be around 110 watts. So yes you don't need 1200 watts.
I have some recordings that are rather demanding. I was auditioning XRT 28's for the first time listing to some Holst Suite in Eb at 12 watts with a MC 402 when there was a crescendo and the amps power Guard lights came on and stayed on and the sound got all mushy and the stereo image collapsed, to much Power Guard protection. Well I was at LMC, so they pulled out a pair of MC1.2 and we repeated the selection. Welll this time the Power Guard lights just flickered and no audible distortion was noted. Now I admit 20 db peaks over a Forte passage are pretty rare, but they do happen. I must have over 100 albums and CD's that qualify and maybe 20 tapes I recorded live where that happens.
There are a lot of circumstances that go into creating your system at home. As Always its the speaker that is the most determining factor. So if you want to experience a semblance of a live performance in the home don't buy dynamically challenged speakers with less than 96 db sensitivity.
Other wise you will be going to the poor house paying for big amplifiers that you think are unnecessary. They are very necessary if you chose a dynamically challenged speaker for your particular listening environment.