As I said earlier, my initial questions have been answered, but I wish to clarify some things in light of recent posts.
Although I am currently surrounded by computers in my studio, I cut my teeth on putting notes on paper and hearing the orchestration in my head, not synthesizers. Most of the music I produce now for film/TV is done with samples but, if it's an orchestral score, always with how a real orchestra would play in mind. I completely agree with the feeling that if you're going to write orchestral music, you should have some idea of how the instruments are played, hence my years spent in formal and private study. Sure, you can use orchestral samples in non-idiomatic ways and create hyper-realistic sounds and gestures if that's the effect you're going for. Then, the orchestra becomes another sound module/synth, which I have no problem with. Just don't confuse that with writing for "live" orchestra.
Of course, brass and wind section players must stagger breathing in order to sustain long unisons/chords. As Rob points out, the ultimate in realism would be to sample sections doing just that, but barring this, the next best option is to loop the sections. (I still have concerns that looping the 1-2 second sustains in the trombones and tuba are going to yield static results, but King Idiot's work on the GOS Grand Detache strings is pretty convincing and musical, so maybe it will work.) As far as triggering the sample again, re-articulating a trombone section sample, for example, is not the same as 1 player re-articulating while the other players in the section hold. KI's workaround may mitigate the problem somewhat, but I still don't wish to double my sequencer tracks and/or Gigastudio slots to accomplish this. Kevin's issue is yet another problem that I haven't personally encountered, but based on how most professional film scores are written these days, could frustrate composers and orchestrators away from the library.
Having said that, I go back to the reason I bought VSL and why I posted originally. I'm doing mockups for a film which will ultimately have a 95-100 piece orchestra, heavy on the brass. The composer is a talented orchestral guy from Australia who has been writing film and concert scores for quite some time, and has a good idea of what is and is not possible with live players. He does not use synths/samplers to write, hence my gig for the month. In fact, he expressly told me up-front that he would not be writing with samples in mind.
VSL seemed like the best choice to get the job done due to its "realism" reputation, but I hit a wall on the very first cue. The score called for a 2 bar sustained chord in the trombones at 71bpm, beginning at forte and swelling to ff on the last two beats. None of the trombone patches could cover the part at this dynamic. I must point out that no one is expecting the live players to have to stagger breath their way through this part. Such writing is a staple of homophonic music found in many scores. The contention that, if it can't be done with VSL's current release then it shouldn't be written, is off the mark to say the least.
As to making my own loops, there is no time, nor do I have much interest since most of my energy is spent either producing music or looking for work. As Peter points out, if a product can't help me meet a deadline, then I'm going to use something else. That's what I meant by the library being unusable. Yes, there are many things about VSL that many people can use, but if it can't do what I need it to do, i.e. something as simple as sustains, then it's of no use to me for that task. That is truly disappointing since, as Rob says, the library is groundbreaking in several ways, yet falls short in rudimentary areas. If this were a $99 brass set, you would have never heard from me, but my expectations have been raised by VSL, and rightfully so. Here's to continued development and improvement.