Hi
@EasyRider - welcome to the forums.
You will find the XT has more similarities to your BMW Nav 5 than it has to the 550.
Take a good luck at the pdf file attached to the first post
here
Download it. You will find the first two chapters relevant to what you already know about your Nav V. As I understand it, the Nav V was based on the Zumo 590. Not everyone who has 590s know the information in there - it will help you when moving forward with the XT.
Much of the information that relates to the 590 as regards route planning, also relates to the XT.
The XT has its own documents - not as a pdf, but as a series of links which are on this forum.
viewtopic.php?t=1464
Have owned Zumo 550, 660 == Now have Zumo XT2, XT, 595, 590, Headache
Use Basecamp (mainly), MyRouteApp (sometimes), Competent with Tread for XT2, Can use Explore for XT - but it offers nothing that I want !
Links:
Zumo 590/5 & BC . . .
Zumo XT & BC . . .
Navigating with Zumo Booklet