Since you're looking at '11 I'd go with iDrive if it was me. But if you end up paying an insane premium for it then skip it. Phone is very doable without navi (I have a '07 and the CCC was so clunky I just got one without it entirely).
'09 525xi | Comfort Access, Moonroof, Softclose, PDC, CIC upgraded
'07 335i E90 (sold) // '03 Porsche Boxster (sold) // '07 Alfa Romeo GT 2.0 (sold) // '06 325i E90 (stolen) // '99 Alfa Romeo 156 (sold)