Funny, I picked up on this thread and I have Meadowlark Shearwaters, the Hot Rod version. They worked fine with my old +/-60 wpc ss amp. In fact, the bass was rather astounding for a two-way, although your room may vary.
Imaging depends a lot on room acoustics but the Shearwaters have the potential to do a great job, in all three dimensions. For orchestral music, I like a good image. For chamber music, timbres and rhythm make the difference to me, and again these speakers do well. Lots of dynamics too.
Where alternative speaker designs may have the edge is in the openness and airiness of the highs. This is not to fault the Shearwaters--they do a great job, but the tweeters are soft domes. Smooth, but not like ribbons, 'stats or Heils.
If you decide later on that tubes are the best way to listen to classical music, the Shearwaters like them. Tubes are what I have now.