Power Uber Alles ?

@erik_squires

have you experienced that bigger amps sound better, or is the overall quality of the amp more important.

The answer is yes.

@elizabeth made some good points I agree with,

“Everything has good points, and bad... they all have compromises.......No one size fits all, No one kind fits all. No ’easy answer’.”

My room is about 18 by 30 feet, with the system mainly projecting to an area with dimensions of about 18 by 22 feet. I have tried a bunch of amplifiers (still sort of looking) on speakers of 90 dB and currently 85 dB. What I have learned that works for me,
- Power matters, particularly if you want a dynamic presentation, in a larg’ish room, with moderately efficient speakers, and you don’t like your sound thin or tonally bleached
- The quality of the power matters too, and particularly the power supply - the ability to double power (or close) into halved impedances is one indicator
- Design implementation and quality of components matter too
- Low output impedance is helpful
- High input impedance is nice for flexibility, and critical if using a passive attenuator, but not necessary with most SS preamps
- Adding two high quality subs and removing the low bass burden from the main speakers was a good move for both amplifier performance and particularly for bass performance and flexibility
- There are significant sonic differences between even highly regarded Class AB, Class A, and Class D amplifiers that go beyond the heat issue. IME, Class AB is probably the most flexible for a wide range of music and listening preferences but each of those classes have their own sonic signature and which you like will depend on what you listen to and what sonic attributes are important to you.....sort of back to Elisabeth’s “no one size fits all”

The OPs question is about power and quality.
With respect to power, in my world, you need to have enough power for whatever speakers you choose, to play whatever music you enjoy, at whatever sound pressure levels meet your expectations for realistic dynamics.  Anything less and you are unlikely to be satisfied with the amount of power, in the long term.
The quality part of the question is both objective with respect to the quality of power (i.e., low distortion and minimal frequency variations), as well as subjective with respect to listening preferences.  
So, the answer is to purchase amplifier(s) with enough power to cleanly (i.e., without distortion and frequency aberrations) drive your speakers to satisfying (continuous and peak)  sound pressure levels.
Musical Fidelity previously published a SPL vs. amp power vs. speaker guide.  I could not find it on their current website but below is a link to a forum thread about "moving from a 150 watt amp to a 400 watt amp"  where @bruce_weiland posts the Musical Fidelity info from their 2009 website (see post dated 3-26-18 at 5:14pm) and immediately following @almarg provides additional useful comments on the subject.
https://forum.audiogon.com/discussions/what-does-moving-from-a-150-watt-amp-to-a-400-watt-amp-get-you