Power Uber Alles ?

Hi Gang,
Another thread that is about to go sideways brought up an interesting question: Is power alone an important quality indicator for you?

Of course, they're nice to have, but have you experienced that bigger amps sound better, or is the overall quality of the amp more important.
Assume you have enough power for a modest living room. If a listener was happy with a particular 100 Watt amplifier, would you suggest they find more power?

Please include experience, speakers, and size of listening area while replying!

Also, for a 12' x 18' living room with 86 dB speakers, what range of power do you think you would personally be happy with?