Assuming they had the same sensitivity and frequency response (of course, they won't, but that is irrelevant), it would sound the same. Really, sensitivity nad amplifier power control how loud a speaker plays, not power handling. Power handling really just sets the upper limit, and not much else.
Don't bother matching speaker and amp RMS power. It's meaningless. In fact, some people intentionally overdrive their speakers (ie, using a 500w amp for 300w rated speakers), since amp clipping sounds bad, and heats the speaker up more than if it was unclipped (if the voice coils in the speaker get too hot....poof. That driver is history)