Fred, a quick comment on one parameter that you mentioned, i.e., rise time: there certainly is a "consensus" on that in the technical literature and it's unclear what you might have read someplace that indicated otherwise. Rise time and the related slew rate measure the ability to respond to voltage changes quickly enough to reproduce the highest frequencies of interest with flat response and low distortion. There are specific formulas to determine the requirements and as long as response is flat to well beyond 20,000Hz, as is typical of nearly all modern solid state units, this establishes that the rise time and slew rate are sufficient(typically anything in the double digits of slew rate)and needn't be a separate matter of concern for the listener.
