Thank you. I agree phrasing is quite important, and I think I learned it in my church organ lessons besides developing a feeling for the instrument you are emulating (in this regard I'm better in brass as I used to play the trombone), but on the other hand the sample has to be really good, too, you can't turn a bad strings sample into a realistic one by the way of playing.
Regarding Tyros, I heard you could import such a library into the Tyros flash by multiple painstaking steps through the voice editor via computer, but not virtually out of the box like you can with the Motif/MoXF. (With the MoXF I had to process it through the J.Melas waveform editor, but that was a simple .x0 import and .x3 export.)