Definitely add the Tech Package w/ Navi. Also the Driver Assist Package or at least a la carte PDC and rear view Camera. The F10 is quite a large car so the PDC and camera, as others mentioned, really help with city parking. With all these options, you're pushing close to the price of a 550. Part of this is due to the fact that the 550 has many standard features otherwise optional on the 535.
2013 BMW X5 35i
Alpine White | Cinnamon Brown | M Sport
2013 BMW 550i
Titanium Silver | Black | M Sport