Well, while not a review, I can tell you that I am already wishing there were many more user chord slots available than the 12 allotted. I can kinda get around this by having multiple instances of SM-4 in the Kontakt rack and changing the midi channel for each.
The thing I am really enjoying is how easy it is to voice your user chords and you can select which/how many of the six strings will be played in that chord just by clicking a button on/off for each string located at the nut.
There is also a button below the fretboard you can click that will show all of the notes names on the fretboard which makes it real easy to select which notes to include in your user chord voicing. Also one for midi note numbers but I have not yet found that as useful.
The guitar samples themselves sound pretty darn good without any EQ or effects applied although I only spent a couple of hours playing with it using AKG 240S headphones. The really cool thing is that I did it on a laptop using the mouse clicking on the keyboard within Kontakt, No external keyboard was required...
While subjective, So far I feel like I will definitely get my money back from the investment and Tracey has been very good to deal with and keeping things updated.
So have you placed your order yet?