Hi Chris
I posted some detail of my fun with MIDI guitar over here. My Roland GI-10 can be configured to pass pitchbend (within two ranges) or to quantise the notes as you bend the strings. I really like the effect of quantising, i.e. as I bend I get note on for each actual note I hit - it gives a quite different dynamic to my playing, achieving rhythms that I would not normally play.
Sensitivity and tracking is tricky - it changes the way you play (which isn’t necessarily a bad thing) because there is a bit of latency (maybe a 20-30 ms - I haven’t measured but will when I have a rig set up) and trigger and release may be unpredictable. (Actually it depends how cleanly you play. If you don’t strike a string well or let a string buzz then you are more likely to have issues that can be masked with normal analogue guitar playing.)
I can assign all strings to the same MIDI channel and use the guitar as a 6-note polyphonic instrument or allocate each string to a different MIDI channel which gives a challenging but interesting / flexible controller. I have not done much with that mode but do intend to play when the Zynth is back together.
My GI-10 is rather old now, circa 1994 so uses the kind of technology that GTR found so frustrating for live use (drifting tracking, etc.) and abandoned but my experience in designing and building transient detectors and signal processing and there not being much interest in guitar synths in the intervening years would lead me to believe that current guitar synths may behave similarly. Maybe Morg can enlighten us on what kit they use and how it behaves.