Agreed, my amp comments would only be relevant to amps that are well beyond the curve of diminishing return. If an amp (cheap or not) specs claimed 1% THD, measured at 1 kHz driving 8 Ohms, and data for IMD, SNR, DN, then of course it most likely will sound different than an amp that claimed 0.1% THD+N, 20-20,000 Hz from 100 mW to rated output, and provide IMD, SNR, DR specs that are average to above average.
My preamps and power amps don't sound better to me than my AVR for my listening habit, so I finally let my 4BSST go last year, but I am not selling any of the remaining ones (may be the Halo A21 eventually as it has been collecting dust..), because I like their build quality, robustness, and the feeling that they are indestructible, and I know if once in a while I want to crank things up while I am alone, and are sure that my neighbors have gone to work or cottage, I can do so without getting headache from distortions.
What I find amazing is how people heard night and day difference when I could tell it was Placebo at work, and/or not really comparing apple to apple, based on circumstantial evidence they provided (sometime subsequently when questions were asked).