Sigh...
Crosstalk: The speakers cross-talk in the room. What do you imagine the actual threshold is for cross-talk to be audible in a real listening scenario?
THD: Again: this feels like a number for the sake of a number. Do you have any data suggesting that any ABX test has shown a preference (or even detectability) on the THD numbers described?
Noise Floor: That's one of the numbers for dynamic range. Again: can you relate this to something audible?
"Highs sound better"; which is really strange since the tweeter is about the easiest thing to drive. Has this been DBX tested? It seems like this might be psychosomatic.
I've owned one pair of speakers that I can recall where amp made a difference (A pair of B&W 801Ns). Bass response was better with an amp that scaled down to 2 ohms well (I used a McIntosh 2120 to accommodate that). Looking at their resistance curve, I think I might understand why.
I assert that amps are "sufficient" and "insufficient", and when they are the latter, we can see why in the numbers.