Oil on the MAS I can imagine could be a problem. I've been running mine for about 6K with it and haven’t had a bit of trouble. It’s important not to over oil when you clean and reoil your filter. A filter right out the box should be taken as a good example as to how much oil should be on it.
In response to cougar, while it is true that these are highly tuned machines and have hi tech electronics, these electronics are designed to measure and adjust the air to fuel ratios. Thus more air flow past the Mass Airflow Sensor would cause the air to fuel ratios to adjust accordingly. This is the primary reason that you can drive your car at multiple altitudes without needing to adjust your carb manually. As anyone that has driving at an area of high altitude and then in area that is closer to sea level could tell you. More air means more power and better fuel economy. It’s really just that simple. Take your Porsche down to phx for a few days and see what I mean. I would also be very surprised to hear that any automotive mechanic would say something to the effect that allowing your engine to breathe better would reduce low/midrange performance, if they do, you should ask to see some credentials.
