I have a Ford, I also have a BMW. Both have nav, voice features, etc.
Ford CAN be clunky at times, but overall it is much easier to use. When you add in the fact that Ford has continued to improve their system (mine is a 2011 system purchased in mid 2010), SYNC just blows the BMW system out of the water. Please remember, this is the touch screen/nav based SYNC system. I've also driven a Ford vehicle without nav, but with SYNC, and I would concur that it is horrible when compared to both BMW and Ford Nav based systems.
Now, BMW is a nice car overall, but with just a few minor changes to the drivetrain, I might have purchased a Ford Taurus SHO (needed to be more RWD biased). If I were to choose between a 3 coupe and a Mustang, I might just choose the Mustang. They are different cars for different things and it's a matter of preference. Overall, I purchased the 550 because it did what I wanted it to do better than the others I looked at. I bought by truck for the very same reason. It does what I need/want it to do better than the others I looked at did.
One thing I would encourage everyone to do when looking for your next vehicle is drive the competition. Don't be a brand snob...especially if you love to actually DRIVE your cars. BMW is a great car, but unless you want the car just because it will impress others, don't buy it because it says BMW. Instead, buy your car based on how you feel when driving it. In doing so, you may find that your next love affair will be with an Audi, a Mercedes, a Ford, a Lincoln, a Toyota, or a Mazda....or some other make altogether.
2013 BMW 550i M-Sport - ZCW, ZDH, ZEC, ZMP, 2TB
2011 Ford F350 Crew Cab Short bed
2006 BMW 330i Premium, Sport, Automatic, Comfort Access
2004 Lexus GS 430, 2001 GMC Yukon, 1999 Pontiac Grand Prix GTP, 1997 Ford Thunderbird V-8