Scott,
There is definitely a problem with many BMW dealers with respect to service before and after the sale. While my current dealer isn't a jerk, I got much better service from my old Infiniti dealer, and I've heard great things about Lexus dealers.
I was in a similar position, deciding between a Lexus GS, Audi A6, and BMW 5-series. The high and low points of each were:
Lexus GS
Extremely high reliability/longevity
Tomb-like quietness
Poor styling (IMHO)
Audi A6
Best fit and finish materials
2.7T engine is awesome
Softer suspension...