I tend to use the digital speedo more than the analog anyway. It's nice that we have both (digital and analog). Is there a way your digital can display in mph? Can't that be adjusted through iDrive (assuming you have iDrive)?
As an "enginerd," I love the metric system. It make perfect sense and is super easy to use. None of this 12 into 1, or 16 into 1 crap.