For what it's worth, I've been happy with the performance of my 4.4. It's quick off the line and gets me up to freeway speed quickly.
I agree with doing a PPI. It won't necessarily find everything (mine didn't see symptoms of the valve stem seals, which popped up after the 1st oil change) but it can give you an idea of what you'll be in for.
Here's the link for the indy shop list. Looks like the closest one to you would be Renton - which is pretty far away. So maybe look at other review sites like Yelp for a shop which specializes in BMW.
http://www.xoutpost.com/bmw-sav-foru...ationwide.html