Rikki, I think Garritan is doing a very good job of producing virtual acoustic instruments at a signicantly reduced byte size. He also has the big version which are excellent, e.g., Garritan Strings.

AJ, you are likely right that it will take something like Yamaha's VL150 plug in to come anywhere near a good sounding Sax. I currently have layered a few sax samples and use velocity switching to get at them. I come somewhat close to that dirty old blues sax (smoke, spit, wheezing and other delightful sounds)....oh well.