Who makes

YEs, and most modern high quality speakers that are not large and use porting and other methods to deliver extended low end bass response out of a smaller package, as is popular with most these days, ARE difficult loads, even quality small monitor style speakers with top notch low end extension for their size.

COmbine that with a lot of the popular and low cost commercial amplification devices out there that also tend to emphasize many features in a small package that most can handle easily that use relatively small and inexpensive power supplies to deliver their watts as well and you have 90% of the reason why so many systems you hear normally have such mediocre sound, even if the speakers are in fact capable of much more.

Its like connecting a fire hose to a house spigot and expecting to be able to put out a house fire as well as the one hooked up to the high pressure (voltage), high volume (current) fire hydrant down the street.

Yes, you are correct, Bob. Here we are talking about power amps & power amps driving speakers so in both cases there is an electrical circuit completed around the voltage source (the amp) which will cause current flow.
I assumed this due to nature of the question from the OP.

The Zamp puts out 12 amperes at 45 watts. It still seems to me that current capacity, along with slew rate, would increase dynamic headroom before clipping. Because 12 amps x 120 volts = 1,440 watts, not 45 watts.
Atmasphere makes a convincing argument for tubes and I can see how his amps could better a ss amp in the right setup. What I don't get is do you want the power of a tube amp at the impedance peak to lower the FR or the reduced power of a ss amp to control resonances? Is this where the whole voltage / power paradigm relates to which is better for which speaker? Because for the rest of the frequency range, this would not matter. Other than nominal speaker impedance.
Is it easier to make a ss amp that can drive a 2 ohm load than a tube amp?
A vented speaker benefits from the control of a ss amp? Would a sealed box benefit from the deeper extension of a tube amp as there is no impedance peak from a vented port? Just that of the driver itself.

The best amp is the one that matches best to the best speakers.

In the end, that's really all that matters, no matter how it is accomplished in any particular case.

Figuring out what will work best with what is the tricky part. The rest is largely subjective.

I've heard all shapes and sizes sound equally excellent, though probably never exactly the same. Pretty close though. The key was always someone who knew how to put the right pieces together and make it all work. That and good (but rarely ever close to perfect) source material to work with.

Only tube amps will ever have that really cool looking retro glow going on to boot though.