Experiences moving from high-power to lower-power system

Dear all,

For years I have been pursing a track of higher and higher power solid-state amplification with medium-to-low efficiency floorstanding speakers. I don't wish to start another tube vs. solid state thread. And we all know the benefits of more, often Class A, power: better headroom, transient response, imaging, soundstage, low-end control. Rather, I want to ask about the experiences of folks who have traded in higher-power for lower-power setups.  What were the tradeoffs? What got better? What got worse? Was it a question of fit with the space? Answers can be from folks with super-high-efficiency speakers and flea-watt amps, tube or solid state, or transitions to setups that are less extreme. 

Thank you,

Paul