Great detail, refinement, mid-price office system?

Only Walker SST.
The probable weakest link - because it is the oldest design - is the int amp - 1993. I am tempted by the North Star 192 system however, but would I then have to get a new int amp to optimize the features of the 192 DAC/Transport?
That will exceed budget, though, to replace both.

How does your current system sound at higher volumes?

I think the place I would look next is to pick up some resolution from isolation solutions. We (Audio Asylum Inmates) are about to get a group purchase put together of Barry Diament's Hip Joint roller bearings. I think these would help considerably. You might want to consider some Machina Dynamica isolation base products as well. These are a really effective way to increase resolution. They might not work for you aesthetically or due to vertical space constraints. The roller bearings combined with the platforms yield even more incredible results than either alone. Perhaps some Neuance platforms would be more practical, but I would see what the roller bearings accomplish first.

My guess is that in the end you will probably need to purchase some high efficiency speakers to get to where you desire. There are some good inexpensive options out there.

Given the performance of your home system I know how difficult it is to settle for less. BTW, these isolation suggestions will do wonders for your home system as well.

Thanks, Wellfed. All great suggestions. Which high efficiency speakers do you hace in mind for less than $2K used?

Well, one I was thinking about is the Omega carried by Duke LeJeune at Audiokinesis.

Omega Loudspeakers

Another would be the Cain & Cain Abby carried by Alan Kafton at Audio Excellence AZ. I notice they have a nearfield version.

Cain & Cain Abby

Perhaps you should solicit responses for a system that provides excellent resolution at low volumes. I've found this to be no small feat even with spendier components, high-efficiency speakers, and lots of attention to the details. Of course this was done to a very high standard that presumably is seldom attempted with a secondary system.