As with most Kontakt libraries set up is very simple. It comes with a manual and all necessary documentation. Installing it is a breeze. All you do is pop in the CD, copy the files to anywhere on your hard drive, and then direct Kontakt to the files. Most of the time Kontakt will find them automatically for you, though.
Once MOJO is installed users will find that it is pretty easy to get the hang of. There are a few screens for features such as key switch options and effects, but these are all very simple. Assigning different articulations, modes, and releases to different keys is easy as well. One thing I found that I don't like about MOJO is that there is no way to save key switch layouts. I don't really like the default one, so setting it up every time I open it up is kind of a pain.
It runs very smoothly. I'm using a Dell XPS Studio with six cores and 6GB of RAM. Some instruments take up to 500MB of RAM, while others don't, so depending on the instrument MOJO is a bit of a CPU hog. It has never crashed on me before though, and it always runs nicely in Kontakt. The instruments take a little long to load. Maybe 25 seconds for some of them. Others are very quick.
I love MOJO for the sounds though. It's the only virtual instrument that replicates all kinds of saxophones convincingly. With the use of all the included articulations you can create some very lively saxophones pieces. Some articulations are overblown, vibrato, and "doit". There are also releases that the user can pick from such as "rip up", and "trills". Some other features are having the ability to choose the amount of players at once and choosing between legato, mono, or poly.
Overall the sound is great, the stability is great, and it's simple to use. It will take some time to be able to create convincing saxophone peices with the use of the releases and articulations but users will get the hang of it. MOJO is the only virtual instrument I own that I use for saxophones and I feel like it will stay that way for a while.