More power for moderate listening levels?

That sounds like a recommendation to change speakers to your fav.

As opposed to choosing what is bad, I guess. Like tuberculosis.

That’s not a contradiction, because I never said to buy speakers to match your amp.

It really comes down to priorities and preferences. If high quality at high volume is a priority then you need different speakers. Its that simple. The power demands of those speakers at high volume, forget reserve, you need hundreds of watts. Need. To use. Not have in reserve. Whatever that even means. 

Tekton makes some great speakers, very high efficiency, great sound, and their favorite amp is Pass. It would seem a match made in heaven.  

But if on the other hand you're totally in love with the medium volume sound, able to understand what's going on and live with the compromise at higher levels, that's fine too. 

Most of what I see here though sounds like trying to have it both ways. Since horses for courses didn't gain any traction how about don't put legs on a snake? You have some fine speakers, for what they are. Don't try and make them what they're not. Doing something up a rope, or into the wind, comes to mind.

At the SAME volume, will a higher powered amp improve the sound quality?

No. It does not work that way. As the great Robert Harley said, "If the first watt isn’t any good, why would you want 200 more of them?" Good question. You have a great amp. You have great speakers. Unfortunately way too inefficient to sound good together at anything more than medium volume.

What nobody seems to want to admit, at 86dB you need 2 watts just to get to 89 dB. Doesn’t sound like much. No problem, you got 25. But remember, that’s measured at 1m. Do you sit at 1m? Not even. Sound disperses at a somewhat different rate for different speakers but the inverse square is a good first approximation. That is to say, twice as far away, 2 squared is 4, you get 1/4 the volume. Let’s say you sit real close, just 2m away. Now you need 2 watts just to get back to 86, which is not very loud. To play 89 you need 4 watts. At 92 dB its 8w. 95, now just barely getting to what someone might consider loud, you need 16, and your amp is just about tapped out. 105 is plenty loud, but 10dB calls for ten times the power, or 160 watts.

These are the most conservative possible numbers. Sit even a little further back, in a normal room with normal absorption, and using average volume not intermittent peaks, you can easily wind up with ten times that, and there are not a lot of 1,600 watt amps. Which to me sounds about right for playing those speakers at satisfyingly loud volume. No wonder your beautiful Pass is strained.

A huge amount of our perception of "strain" is tied into volume. With seriously inefficient speakers such as these its just real hard to get the mind around the fact all that power is going into.... not much. Just wasted. Not even going into heat. The speakers can handle much more. Its just a bad design, for anything other than moderate volume listening.

Which, remember again, first thing I said, you have great speakers and a great amp. Just not great if you want to listen at high volume. Horses for courses.

LOL!!! I was writing while you were writing. First thing I checked, your speakers are hopelessly inefficient. Harbeth has the hutzpah to say they are easy to drive! Not at 86dB they're not! Doesn't matter the impedance! Now you know why you see all these guys in love with their speakers searching searching searching for the amp. Its not the amp. Its the speakers. 

Also notice I didn't need any details. I worked this all out simply based on your first post.

It doesn't work that way, and we don't need to know anything about your room. Geez Louise! This is because amps and power don't work anything like the way the vast majority thinks they do. Its perfectly possible you could find a lower power amp that sounds hugely better at both low and high volume. Class A has nothing to do with it either. These kinds of generalities sound all logical and certain but they break down real fast the minute you hook up the exception to the rule.  

You don't mention the power of your Class A amp. But that doesn't matter either. Unless its like single digits. Because once you get up around 20-50 watts then its not the amp. Its the speakers. If yours are low sensitivity (92dB/1w/1m) then it very quickly becomes almost impossible to find an amp powerful enough to play them loud. Particularly if they are below 90, then you can pretty well forget about it. This is why you see all these guys searching around for the right amp. Its not the amp. Its the speakers.