Does the power of an amplifier really matter?


Excuse my ignorance, but I am trying to understand the meaning of amplifier power. A doubling of amplifier output power results in a 3dB increase in sound-pressure level. So, if I listen to my stereo at a volume of say, 70 dB, what is the difference in a 100W amp vs. 250 W amp? If I listen at 70 dB, is more power delivered to the speakers with a 250W amp vs. 100W amp (resulting in better driver control)? I am not sure that is the case. Is it that a higher powered amp delivers a given amount of power more cleanly? Not sure if that is true as well. Can anyone educate me on this fundamental property of amplifiers?
number1cuban
So when the cannon goes off in the 1812 Overture, you guys don't use the subwoofer to take over? Does any body know what's the frequency of that canon in the Overture? Your full size speakers can deliver such power and such low frequency? I am just in awe, and I am afraid to find out what speakers do you guys have b/c I may inherit a bug that I cannot afford. However, please do tell, and I am all ears. :> )
Some "low powered "amps will power speakers that simply don't work with other amp designs with much more power. The vintage Levinson ML9 (get that right?) was a pure class A monaural design with a whopping 25 watts into 8 ohms....and 50 into 4.....and 100 into 2....and 200 into 1...and it WAS rated at 400 into 0.5 ohms....

I would pick up a pair of these if they show up in good condition at the right price in a heartbeat.
The levinson ML-9 is Class A/B and it was 100 watts per channel in 8 ohms. It is the same amp as the ML-3 which had 200 watts per channel. You are confused with the Levinson ML-2 which were mono 25 watts class A and were used with Quad speakers mostly at the time.
Power crazy....it started in the 1970s...you had to have 100 wpc.the more power the better....until today were 350 wpc minimum....please.