DG, regarding GOS, that was a looooooooong time ago. I actually did like the ability to program bow changes. Unfortunately I never had much success with the library as I was one of those individuals who had nothing but trouble trying to get ye old Giga Studio to work properly. As for forcing bow changes, the samples were set up in two banks, mapped to two different sections of the keyboard, with down bows in one set, and the upbows in the second set. You could program bowing however you wished. The downside was that when doing that, the notated part ceased to correspond to actual notes as the upbows (IIRC) were typically placed three or four octaves higher on the keyboard. The ranges of the instruments were generally not quite full range.
Overall, for the time frame that it was released, it was a major breakthrough. IIRC, it was the first major strings samples library of its kind, and even predated VSL (I think). It was very different from the later GPO stuff, and was sampled at a much more in-depth level, with better overall sound. Would it compare to VSL? No. As it was written for Giga Studio, the library has long since become obsolete. Even its design had become obsolete prior to Giga Studio's demise, and the library has not been supported for several years.