Purpose of power handling in the specs?

@erik_squires   cool calculator thanks.  So my 96dB speakers that claim they can handle 600 watts input (I'm driving with less than a watt) will generate 124dB at one meter....

Indeed shocking.

Important to note that speaker makers are usually a little optimistic with their measurements, but they should be from anechoic (no echo) testing.  In room performance will vary, but the power to volume ratios (dB) will remain constant.  3dB more power = 3dB louder until compression sets in.

There was a quote, I think by Art Dudley, " Why do you want 200 more watts if the. first 5 sound like crap"   or close to that. 

Be careful, tweeters and midranges get burnt out quick from under powering.

   Watch the vol knob, and listen for breakup in the highs and minds. 
 

Don’t take much to fry a tweeter or mid coil  

My speakers are rated at a measly 250 rms Peak I believe, and are powered by 650-700 watt rms monos at 8 ohms,

the open airy, non fatiguing sound is from the massive headroom, and the amps barely or. Not strained at all during playback. 
 

I love this, which is why for crescendos and heavy double bass, or just a orchestra balls out section, you need the headroom, and the amps ability to produce the watts needed to not clip or strain. The baby bunny fart amps to me are worthless, I’m mostly rock,blues, rock, metal, some acoustic, when volume is needed you will need the amp to produce ample power, current to not clip the music. 
 

even a Normal mid volume playback will need 200-250 watts at a minimum to reproduce the music at peaks.

auditioned lots of the flea fart amps, none come even close to producing the power needed.