I have the demo version, I've spent enough time with it to know that I want to learn to use it better. I am not getting the results I'm hoping for, yet, but I think I will soon.
This is a very deep library! There are tons of controls, tons of options, and it will take some (most?) folks a little bit of time to master it. I think it's absolutely brilliant that KH offers the demo so you can figure out if it works for you. Demos from users often fail to show a library at it's best... demos from the developer tend to lead you to think this is the best library ever... so having the actual library to work with is brilliant.
I would STRONGLY recommend that anyone looking for a flexible solo/small ensemble string library spend the time to download the demo version.
I hope to be able to post something demonstrative soon...