There was just a review of idrive and nav in the Jan issue of Automobile magazine and BMW was actually ranked the best and easiest to use. Better than Ford MyTouch, Toyota Entune, Hyundai Blue Link, Cadillac Cue and Audi MMI Touch. It specifically said it was best in Navigation.
1995 325i,1996 328ci,1997 528i,1997 Z3 2.8,
2001 X5 3.0,2001 330i Conv,2002 M3 Conv,
2003 M3 Coupe,2004 M3 Coupe,2004 Z4 3.0,
2004 X3 3.0,2007 X3 3.0,2007 335i Conv.,
2013 X1 28 sdrive M Sport, 2014 M235 on order