The two qualities that I listen for is timbrel accuracy and if I can hear "all the way back" into the hall or venue. The Orchestra when reproduced should also convey a sense of power and weight,both ends of the spectrum. If all this is conveyed to the listener, congratulations on a fine system.
Enough detail or too much?
When I go to listen to the orchestra play, the music never sounds as detailed as it does in some high end systems. The closest thing that I have heard to the "real thing" are some of the older nos tubes. There is some smearing but real orchestras do sound somewhat smeared. It seems like the area to get right are the violins. If you can get the violins to sound silky and smooth, that would be the way it sounds, to me at least. Bass always seems to sound somewhat boomy in a big music hall. The instrument that seems the most difficult to reproduce are pianos. I do not know how any system can reproduce the sound of a real piano, at any price. The weight of the notes are so unique, I have heard some extremely high end systems and none get it really right. Just curious how others feel.