"Best for whom?" is always my question. I actually think playing speakers loudly, when that’s NOT how you listen to music is a terrible idea.
That’s like needing a family van and racing it across the Mexican desert.
Test/listen to speakers like you live.
Leave the PA testing to live music performances.
I see now I should’ve specified systems that come remotely close to bridging the gap between live, unamplified dynamic range, and those systems that merely playback recordings such that they sound like a miniaturized ensemble, with a clearly obvious smearing or veiling of transients and decay. In my experience, the systems that can sound great at very high SPLs also perform best at low SPLs. And it’s not so much a matter of speaker efficiency, rather, it’s a matter of total system distortion and headroom. The lowest distortion drivers remain the lowest distortion drivers whether played loud or softly, especially played softly. And if you know much about component contribution, you know the speaker’s driver quality is paramount, similar to room acoustics in that regard.