Thanks everyone! I appreciate the advice. akg_ca, last night I was thinking along the lines that you laid out - sort of like high torque / low revs vs. low torque / high rev horsepower; e.g., a 6 cylinder and 8 cylinder with equal power will never feel the same. I just don't know how to read amplifier specs to identify whether an amp is high current.
I spoke with a salesperson who advised me that if I was unhappy with the sound, it had to be my speakers rather than the Marantz gear. Needless to say, I found myself struggling to give any of his opinions any credibility.