I currently have a tricked out 2009 A4.  I like it but its small and altho the A4 and A8 are expertly designed, they fall short in the midrange A6.  BMW picks it up and then some with the new 5 series.  I am going to sell my A4 and I was thinking about leasing the new 5 series.  Supposedly they also come with nav for $579/month.  Has anyone done this?  Do they give you a stripped down version of the 5 series?  Is it worth it?

Any help would be greatly appreciated.  I have never owned a BMW and I do not know much about them.  

Thanks again.

Mike