I think a large majority have Nav. So if resale is a consideration...
Although I think there will be at least some enthusiasts seeking the non- Nav and 6MT optioned cars years from now...
I much prefer the dash without Nav... but if you prefer it with the double hump... get what you want more.
Present: 2013 M3 coupe (Azurite Black, Black, Piano Black)
Past: 2010 335i coupe (Monaco Blue, Cream Beige, Grey Poplar)
+ miata nut (2004 GT/LS and 2013 GS/Club Edition)