Hi,
This is a most interesting thread or conversation. I've listened to all the examples and there is a lot of improvement that is audible in the course of events.
Some remarks however. I read that MIR was used to define the room. Actually, MIR isn't quite fit for small ensembles (Dimensions, 4-4-3-2-1 or something of that kind?). And equalising is not the miracle solution either. The way the samples sound (harmony connections, articulations, Xfades...) will be as important. 3-chords moving about in a limited low area will sound dull and obscure. Some variation in tonal height could brighten this up, provided this is the wanted of course. The dimension samples have been recorded with ultimate precision and there's little EQ that could improve their richness. I would only use EQ-ing to help them localise (less high frequencies (= less presence) for more distant instruments...) and to filter the master from unwanted uppertones. You really don't need a high-tech EQ-program for that. VSL offers a very good one in the Vienna Suite or any DAW has one on board that will do exactly what you want. For the rest, choose dynamic articulations that come near to a live performance: bow movements are not continuous equal movements, there's always a dynamic difference in it (start to stop, an attack, a diminuendo or crescendo, light, heavy pressure, short/long bows, all of these present in the Dimensions). A good advice: start the Standalone VI and fiddle with the articulations, while you play your chords and try to make a good choice to your taste and to the colour wanted.
I wish you good luck!
Max
PS: here's an example made with the same strength of Dimensions mentioned above:
Example: Rameau, Contredanse