I agree with everything said here. If you enjoy the art of improvisation, the solo feature is really super. I've gotton many ideas by choosing the solo function on Swing, Bossa, Uptempo Jazz and have improved my playing.

You can take a tune like "All The Things You Are" at a slow tempo and gradually speed it up and learn a lot. This tune I find for me is one of the hardest tunes to improvise on. I still don't understand the chord structure after all these years.