Coming back to the OP's question: Amplifiers are not independent commodities. You don't gauge their worth and put them in your closet, waiting for the to appreciate for years before you take them out and sell them still in the box.
Who cares if an amp performs well on speakers you don't own?
Amps are part of systems, tightly coupled to the speakers. When evaluating the performance it is the system behavior that matters, not a test bench and not in a system you don't own.
In general, yes, most amps whether solid state or tube are more impedance dependent than we'd like to believe. Using a powered bass section in a speaker will stress this particular issue less than a traditional multi-way speaker would. It does not by itself change the value of an amp, unless you are a reviewer, of course. :)
Who cares if an amp performs well on speakers you don't own?
Amps are part of systems, tightly coupled to the speakers. When evaluating the performance it is the system behavior that matters, not a test bench and not in a system you don't own.
In general, yes, most amps whether solid state or tube are more impedance dependent than we'd like to believe. Using a powered bass section in a speaker will stress this particular issue less than a traditional multi-way speaker would. It does not by itself change the value of an amp, unless you are a reviewer, of course. :)