The new Commander 112 configuration utility includes the option of using Fixed or nonfixed side views. I've seen the definition of fixed side views in the panel.cfgs of other aircraft I own. On the other hand, I've not noticed anything "missing" or different when I fly aircraft without this option. How are these different and what are the advantages and disadvantages of these? Thanks.

Fixed side views refers to bitmap pictures of the side views vs using the VC views when you look to the sides or back. If you are flying from the VC you won't even notice these but if you are flying from the 2d panel and use your hat switch to look around you will notice a difference.

Fixed side views are only really needed for planes that have an option to completely disable the virtual cockpit for performance reasons (like the Dreamfleet Baron). Without fixed side views, you'd see nothing out the side of the airplane :)Other than that, it just comes down to personal preference.