Amp power will only make a difference at very high sound levels assuming the speakers you are using even require more power (driver size, frequencies played and impedance being the major factors). The difference really only applies to distortion.
Otherwise the power simply goes unused.
Anyone who has utilized a switcher to test sonic character between 2 solid state amps of similar design type (e.g. Class A/A/B) will know just how impossible delineating any difference in sound quality really is. The only variable is whether an engineer specifically designed an amp to filter or enhance certain frequencies through the use of various components. Most engineers strive for a flat response curve as it related to the most accurate sound reproduction a vendor can provide.
An amp of Richie's size will only drive the speakers into a physical excursion limit if the volume is turned up too far (the cones will sound like they are slapping). More power does not equate to an infinity of SPL increases.
I have maxed out my M60s with a 225w Anthem amp which is not of a dual mono design. However my much larger Tannoys can take more power as that same amp will run these speakers into distortion at elevated levels.
