Don't bother with those descriptions. I read into them a year ago, and it nearly drove me insane.
The only way an amp would be "bright" or "warm" is if it had a 3 or higher dB lift or recession in any one frequency range while driving the speakers. Axioms are an easy load, so if the response changed this drastically while powering them - that amp is trash. Solid state amps have been around for over 25 years. By now they know how to make them with low distortion, high damping factor, flat frequency response, low stereo crosstalk.. you get the idea: neutral enough so that outside of power, if it's well designed there's not much else to compare.
The NAD and Rotel are both great amps that measure well.
if they're halfway decently designed, and you're not driving two drastically different models(50 wpc vs 380 wpc), they'll sound the same.. Save yourself the headache and go with the better deal.
When comparing two
well designed amps that measure well, blindly: I challenge anyone to hear a difference.
