The PTO would normally only get used by someone who installs a dump body or snowplow lift pump or something like that.
I have heard of a PTO generator, but that application was for the back of a tractor, and was a 25KW generator, about 24" cube, and would not fit directly on your transmission anyway.
I can not think of anything that you might attach to the PTO, so why have one?
As for the navigation, it was WAY to expensive for me to pick that option when I was going to order a new Transit. . . I bought a Garmin at Wal Mart for only $100. And if something happens to it, it might be replaced much less expensive than taking it to the dealership. .
Fred,