Watts! How many do we need?

As others have said, meters, even digital ones, are s-l-o-w. Even on digital recorders, the meters are too slow to see "transient peaks", which is one reason manufactures recommend recording with the "peaks you do see" topping out at -12dB. This allows enough headroom for those transients such that no clipping or compression takes place.

So yes, having more watts can be a good thing - as long as the slew rate of the amp is capable of keeping up with the music and offering those louder transients that might last less than 1/100th of a second, such that the music sounds as "real" as possible.

So, when you are looking at meters, you are more or less looking at what the continuous output power is, averaged over a significant fraction of a second, therefore yes, you will see that most of the time the amp is putting out 1W to 10W at even "loud" volumes. 

Most of the time, I'm using 1-2w listing to the radio. If I want to rock out, or make the house vibrate I use around 50-60w this is out of a 200w amp. At 100db (system can do well over 100db without clipping) at 60w, there will be 100+w peaks.

Since it takes double the power to produce 3db gain, it's good to have all the power, and use it when you want it. Generally a 200w amp will sound better at 50w, then a 50w amp at 50w. Plus staying that far under the amp's peak power produces much cleaner power to the speakers. 

Most of the time, we will all be happy with a 20w amp, but I would never buy anything under 100w

Anyone that listen at 113-115db are either def or stupid, or if doing it routinely maybe both?

If you are not def, is it then something you aspirer to be ?

Why would a music lover try to intentionally destroy one’s hearing?

As older we get our hearing for most people deteriorate and unfortunately for many it hinders their ability to function 100% in social gatherings and for some people they choose to redraw a bit from social life.

Also as it is now, there is nothing you can do if getting tinnitus which even is a much bigger problem.

i worry about the younger generation that blast music into their ear canal’s with in-ear headphones, I am guessing that most of them will have big hearing/tinnitus problems before they are 50!

Don’t get out much, do ya? Lots of folk go to a monthly concert. And they are played in the 113-115 range. Many times, much more than that. You think all those thousands of listeners at the live performances are going deaf? It better hurry up if it’s going to affect me. I’m almost 70 and have been around loud race cars my entire life.... (And a dash of music). You sound boring! But enjoy life however you want it, I know I have enjoyed the heck out of mine.

https://youtu.be/q_-Z0ZVXWZg

https://youtu.be/6O9r_1gnpg0

There's nothing like a well designed class A amplifier to bring out the best  performance in your speakers.  I once owned an original Bedini 25/25 that was a nice match with my 15 ohm Rogers LS3/5A's.  It was also supposed be a great match for the original QUAD ELS 57.  The Bedini 10/10 was also a good choice for the ELS 57.  One of the best sounding and most powerful class A amplifiers that I have ever heard is the Classe Audio DR3VHC. It was one of Classe Audio's first products when David Reich was running the company. 

My advice, take it or leave it:  is to note what the speaker manufacturer recommends as a minimum power recommendation into the 8 Ohm load of the speaker, then note what the minimum (not nominal) impedance is, then double down the recommended power for each halving of impedance e.g. 10 Watts into 8 Ohms, 20 Watts into 4 Ohms, 40 Watts into 2 Ohms, etc.. When faced with a non-standard impedance, drop down to the lower standard amplifier rating, for example for 3 Ohm minimum speaker load go to the 2 Ohm standard amplifier ratings unless the amplifier manufacturer offers non-standard ratings (such as the Benchmark amps). Using that as a minimum power need. While room size and desired output levels will actually determine how much power one will need, as a general rule of thumb for most people, in most rooms will most probably be better suited by doubling the manufactures minimum power recommendations into that minimum impedance as noted above for satisfactory results. The important thing is actual power into that lowest impedance. I don't recommend relying on so called "stable into X load " claims, as that only means the amp won't go into osciallation when presented with that impedance. it is not a guarantee of power output or distortions levels into that load. Don't be swayed by manufacturers, dealers, etc., annecdotal suggestions; let them put it writting. Using the above considerations can go a long way towards preventing speaker damage, and offering satsifying sound.

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