It's interesting though, that he sticks to easier instruments to emulate than the saxophone...

As I mentioned earlier (with reference to the E. Piano smoothness), you start to use sampled libraries with dozens of samples per note, and much of the shortcomings of samples can be mitigated. But you are still faced, especially with the saxophone, which has probably the largest timbrel difference of any wind instrument for even one note, that simple blowing doesn't really begin to cut it. With reed instruments (and brass), there's a LOT you do to change the timbre by mouthpiece pressure, biting down a bit harder on the reed, changing the angle of the reed in your mouth, how hard or softly you tongue the note, how you shape your mouth, things like that. It doesn't boil down to such a simple thing as how hard you are blowing, which is all a MIDI mouthpiece tracks. Some of the dedicated sax controllers tracked more parameters, like bite strength, but that's not much use if you can't already play a reed instrument, and if you can, why use emulation in the first place?!

The combination of modeling AND samples seems to be currently the best way for sax emulation, but again, NONE of this is available in an arranger. SA2 seems to be King of the Hill so far in arrangers, but again, you have to play what the sample set does best, NOT necessarily what you want to do!

Eventually, we are likely to see arrangers based on something like the Kronos engine, which supports various synthesis options including samples AND modeling, and things may well improve. But until then, emulating saxophones remains an exercise in frustration, forcing you to play what the sample set does best rather than whatever you feel like..!