JimH - If you post a survey on the Saturday night of a U.S. holiday weekend, and then close that thread on the morning of the Monday holiday, then your survey will have no population of U.S. MJ users who went out of town for the holiday. That may or may not affect the outcome, but it does seem odd.
Anyway, I think you should make MJ as complex as seems logical to make the program perform well in those areas for which you tout a solution. Many novice users become average users over time, and some of them become seasoned users. As people use MJ more and more, they want to do more and more things, and having the switches available within "Advanced" sub-menus makes the product more attractive, while not harming the novices in any way. By "those areas you tout a solution", an example would be jukebox behavior. One reasonable option would be to have the jukebox purge the list of already-played songs, so why not offer that option? Another example is the command line interface. It is very helpful, but some beefing up is needed. Offering some of these things eventually leads to the commitment to improve them.
I think the more important question is how to structure the user interface to the "complex" options. I personally hate having to set a program to "novice", "average" or "expert". I think the interface should be the same for all. Just use a logical menu structure, providing "Advanced" buttons which take you to sub-menus, and even providing "Expert" menus below those. This lets novices slowly become experts.
Scronch