I have had my 401A for many years and love it! I use it more than any other machine.
I have only the #1 cam, but it creates quite a variety of stitches. There is a chart of stitches and the settings for each inside the door on the top of the machine where the cams go.
The only thing I haven't been able to do with it is FMQing. It will always break the thread when I try to move to the left. That's ok, though, because I keep my old Bernina set up for FMQing at all times.