I come from a keyboard background, so naturally I had some difficulty in this "fretless" experience. But this opened up a ton of opportunities for expressing myself. After a year I still discover sounds, and new firmwares do come out and add presets and sound capabilities.
I highly recommend the Haken engine, its physical modelling is fantastic to my ear. Of course I use it with vst instruments as an mpe controller too. But standalone is so good..