I was having oil consumption problems with my car. It was using around a quart every thousand miles. We put at least 2 thousand miles on the car every month. I had to do something, and decided to go the PCV route. I followed the instruction in this post:
http://www.xoutpost.com/bmw-sav-foru...-problems.html
I also added a catch can. Five thousand miles later, and the car hasn't used any oil. I drained the catch can at the same mileage. The can had collected a 4 ounce mix of mostly water and a little oil. It had a milky appearance. Without the catch can, that mess would have collected in the engine. If I didn't drive the car so much it would be sludge city.
I am glad I went the route I did instead of replacing the factory CCV system.