Having had a V8 and now a diesel X5 the only disadvantage I have seen is the 5000 RPM red line on the tach. The numbers are bigger and more spread out though. It goes up hill better than the V8 did and will slightly slower from a start not bad for the trade off of not seeing the 12 MPG anymore.
2010 Space Gray 35D
2007 Space Gray 4.8 Returned to BMW