My .02. I've a BMW in one flavor or another since 1979.

I picked up my current E70 ( two of them actually ) in Dec 2009. (Delivered in late Feb 10)

One was a X5M the other a 3.0 MSport. Both have been the worst BMW's I've ever owned. I sold the M after about a year, I still have the MSport.

The M Sport has been in the shop a total time equal to 3 months since I took delivery. It spent it first 6 weeks of life in the shop because it was "bricked" when they tried to re-flash the firmware trying to fix several software issues.

Neither car had any mechanical problems. Every issue has been related to fit/finish or software. The tailgate on both cars rattled from day one, the MSport tailgate still rattles today. That's just one small example.

Just two weeks ago I canceled my order for a X5 because, frankly, I got cold feet when I thought of all the issues I've had with this car and I just didn't want to chance it again with a new car.

I purchased a warranty and maintenance extension and decided I'd drive this car for another year or so and make a decision then.