On planars, maybe I'm a heretic but I haven't heard one that generates convincing instrumental tone. I don't mean transient behavior which they obviously excel at and I don't mean image which they can do passably. They can give a nice presentation of space if properly set up.
But as far as the life and breath of instruments, I haven't heard it yet. Granted, my experience is limited to two occasions: A big pair of Maggies in a room that was probably too small, and a pair of the current $10k Martin Logans run by big Mac stuff in a dedicated room. Each session was 45 minutes or more with my music at "convincing" volume.
The Martin Logans had a very nice bottom end, as they used powered, dynamic bass systems. But, it didn't blend with the panels very well.
With ribbons, I've had similar experiences, especially with VMPS.
Am I missing the experience? Is it a matter of preference where tone isn't the main priority of these types? So many folks like them that I must be missing something. I guess none of my experiences have included FAT tubes pushing them. Maybe that's part of it.