Speakers that do pianos really well

I recently had the good fortune to listen to a half a dozen pretty well-regarded speakers back-to-back. For these kind of sessions I like using piano recordings - either solo or jazz trio - as a measure because, to my ear at least, it seems that speakers that can reproduce piano really well seem to be pretty well sorted on everything else. The surprising thing was how many of these speakers did NOT do piano well. Of the group there were only two - Vandersteen and Verity - that I thought really captured the big chords, shadings, timbres, and reverberations cleanly and naturally. The rest - and I'm not going to call them out by name - offered a mixed bag of over-brightness, distortion, and general unnaturalness. I was very surprised by the results as I expected better from some of these speakers based on their reviews and reputations. So my question is, Does anyone else use the piano as a litmus test, and what speakers do people use that they think do pianos really well? Regards.