More power on hand whether you need it or not is normally a good thing, but unless the power is put to use, it won't improve sound quality. Obviously that assumes the amps being compared are designed to be transparent, with distortions well below a certain point.
People who reported hearing the so called huge, big, massive kind of difference simply by changing from one amp to another might have heard such difference for a variety of reasons that may or may not apply to you. The same go for the another side of the story, many reported no difference whatsoever. There are just too many variables, some are simply facts and figures related, whole others are subjective and that include people's preference, preconceived ideas and how prone they are to the Placebo effect.
If you are to stick with facts and figures, then it is a good idea to search out all available bench test data for the products being considered, instead of going with what others are telling you, that may not even be facts at all as they could have been affected by other subjective factors or, again, facts but not applicable to you.
I would like to add one more recommendation, that is, before making your decision, use the often linked peak spl calculator to find out how much power you really need. Then double it to determine your targeted power, to ensure the amps being considered will not be the bottleneck under the worse conditions. If you go beyond that, there is no problem but then you won't get any further SQ improvements and you have to be a little more careful to avoid damaging you speakers.
