Until such a time I can A/B compare my current Outlaw 2200s against some Hypex NC400s, I think all this talk about Amps: having unique sound signatures, being delicious, being chocolatey, being liquidy, being crisp, whatever... is bordering on the ridiculous.
One very talented Speaker Designer
and musician has said, too, that exotic capacitors don't have a sound signature, either, and this has been echoed by many.
I know, there is the other school that insists that because a Cap is impregnated with Gold-Oil, or cost $150+ each, that it is magically better... and these are usually the same people who insist that speaker cables like AudioQuest or Kimber make a difference, or that you have to "cook" your speaker cables and listen for 100-200 hours to break in your speakers, or that Amps make a difference, or that cable risers make a difference...
Should I keep going?
Clearly you are suffering from a First-World, 21st Century problem: Amp Decision Paralysis and a case of Upgraditis. Only you can solve it for yourself. It is your system and your ducats.
If you want to post reputable third-party bench tests and discuss the results and the audibility of any noise in the signal, I think many here would gladly engage much more freely.