I'll add. I'm a Polk guy but if we're talking amps
I own Emotiva. I would love to try higher end amps. Sure, just like a speaker cross overs, not all are made from the same quality parts. If everything was made from the same stuff, it would sound the same. But this is not the case.
I go for Emo due to my allowing, or disallowing budget. What gets me, is someone telling me my A9's don't sound any different whether I'm powering it with my AVR or my 200w amp or my 300w amp. The sound fact is, my A9's sound different depending on the power I use.
Most will agree that speakers sound different. That alone tells you that speakers have different personalities. In the case of my Polk A9's, they will sound bright under "normal" or non amped conditions. When powered with an amp, the brightness tends to warm up a bit. How do I base this statement? I did an A/B test, AVR to 300w amp, back to back with the same songs. With the AVR, the highs were bright, the cymbals tagged on a lot of "S's" to the end of them. When amped, the "S's" disappeared, the cymbal hits were sharp and precise.
A guy can feed me all the science he wants to, but unless he's spent some time in my room with my gear, he's just giving my written information without any direct firsthand experience to the current situation.