Thanks for the comments, guys!
Guy: These did take a lot of time to do, but since I tend to spread the work out over a long period I couln't tell you exactly how long each one took. The hardest things for each mockup... Well, for the Bruckner, it was definitely getting a good balanced sound out of the orchestra. So much of the piece uses much if not all of the orchestra that making sure certain instruments aren't overpowering was quite challenging. For the Mahler, aside from tempo interpretation issues, there weren't any hugely challenging parts. Unlike Bruckner, Mahler is very specific in his articulation requests, and 19 times out of 20 VSL has the requested articulation. Balancing was an issue in the coda for the same reasons as it was an issue with the Bruckner.
Bruce: I use the medium stage in gigapulse, with every instrument run through separate reverb instances. After this, I decrease the width of each instrument a bit for stage placement - I've found that width adjustements do almost nothing if I use them before processing gigapulse. After this, I have a pretty good close-up concert stage sound. Finally, I run the entire thing through a large concert hall impulse in SIR, with most of the early reflections cut off. The concert hall sound is still a work-in-progress for me, but until MIR comes along, the method I just described works pretty well for me. I use just one computer, a PC. [[;)]]