250 watts: why so much power?

I have seen some really high powered SS amps on the market and I am wondering why so much power? These amps must get really loud. It sounds that they could easily blow an ear drum or two.
Matchstikman: I just checked things out playing the same recording set to the same volume level. The mains are spread appr 12.5' apart ( center to center ) and toe'd in a bit. While this is not ideal for two channel reproduction with these specific speakers, this is my HT system and i have things dialed in for optimum use with a large ( two eight's, dome mid, dome tweeter ) center channel. As such, i need to spread the mains out just a bit more than normal, which also results in a very wide soundstage with excellent center fill due to the center channel taking over on movies. Even with this wide of placement and the center turned off for standard "stereophonic reproduction", imaging and soundstage is quite acceptable. Since I was using the system in 2 channel mode via the mains only when i made the above comments, that is how i measured it.

Ambient noise level in the room is below 50 dB's, which is as low as i can measure. At my seated listening position and the meter just behind where my head would normally be, I am hitting peaks of 108 - 110 db's sitting 10' away from the speakers. The average level of the recording is easily 20 - 30 dB's ( and sometimes much lower ) than this. As such, there is a great deal of dynamic contrast as the tempo and volume changes during this specific performance. This is a very exciting Classical performance, even for a "rocker" like me : )

For those that are "playing along", i'm using a stock Realistic 33-2050 analogue SPL meter. It was set to the "C" weighting and fast response. I also have a highly modified version of the same meter that is much more linear in response ( and would have shown higher peaks ), but i used the stock RS meter so that others with such units might be able to do a more direct comparison. Sean
More important than playing "extra loud" is the ability to play music at a moderately loud level without the clipping distortion and compression you would hear when using an amp that is not quite up to driving the speaker load. Its not all about your amp playing louder, just being able to handle the demanding peaks and keep control during complex passages.
Another dividend can be improved bass control and quality. Some speakers dont need much power but still respond in the bass region. Matching the speaker to the amp is the most important aspect.
I leave my amp on all the time. Will a 300 wpc amp consume about 3 times more electricity than a 100 wpc amp when idle?

Also, a speaker with 8 ohms impedance harder or easier for an amp to drive than a 4 ohms speaker?
More power hopefully mean a more authoritative and controlled sound with more of a relaxed ease in the musical presentation with greater and more life-like dynamic swings. By relaxed ease, you do not feel that the amplifier is pushing it's limits as it's just humming along beautifully.

But all the above can certainly be accomplished in a lesser powered amp to a certain degree. Generally, it's just cheaper and more conventional to add more wpc.

Ulimately, the wpc is only one of many factors that determine whether an amp is worth living with.

But still wouldn't want to be without those wpc's. At least not with my current speakers.

Matchstikman--to answer your questions to me: (1) there are simple formulations as to efficiency. If I remember correctly, and I'm a listener, not an engineer, speaker efficiency is measured in decibels of output per watt of power input. Speakers rated under 90 db. are considered more or less inefficient, over 90 more or less efficient. But it's more complex than that: my speakers were just upgraded, and while their output rating only increased by 2 db., the manufacturer's power recommendation went from 200 watts per channel minimum to no upper limit to 30 watts minimum, 300 maximum. Inefficient speakers driven with inadequate amps tend to sound opaque and closed in. The inevitable tendency is to turn up the volume at the preamp, which only makes the problem worse, because the power amp is now working even further outside its comfort zone. My own experience is when I have added a more powerful amp or switched to more efficient speakers, I wind up listening at a lower volume because more detail reaches me, both on quiet passages and loud ones. (2) I listen at a volume I can get away with in a New York apartment, which isn't all that loud. (In fact, I use a 4-channel system, because the rear speakers increase the sense that the sound is filling the room without my having to blast the overall level.) (3) 22 X 13.5 X 9.