Good topic. I am of the mindset that, in general, people tend to underpower their systems. Although a certain decibal level may be produced by a speaker, it does not guarantee that it will be able to properly delineate the details. The hallmark of underpowering is not clipping, but a lack of focus when things get congested or trouble with huge dynamic contrasts. These things, to get do them correctly, need a certain power reserve. Perhaps the ratings for lower power on speakers are as much a nod to the market constraints.
With that said, there may be some great amps of lower power that do many things quite well, with certain types of music, in smaller rooms. However, having absolute control of the bass, clarity and soundstaging during congested passages, and the proper speed for dynamic shifts may be the downsides.
With that said, there may be some great amps of lower power that do many things quite well, with certain types of music, in smaller rooms. However, having absolute control of the bass, clarity and soundstaging during congested passages, and the proper speed for dynamic shifts may be the downsides.