Gilly----thanx for the reply. They weren't against changing the fluid early, I was just trying to determine if there was a better way to spend $200. Guess not. Admittedly, half that cost is the synthetic fluid, although I didn't think to ask if they planned to extract more than the 3-4 quarts you mentioned.
I figured with the sealed system the procedure wouldn't exactly be like changing it on my Ford; as you mentioned, there is no way to even check the level of the fluid without their computer. I guess I will find out how much fluid is actually exchanged with the dealer's procedure and weight the advantage. I do feel like it's something that should be addressed if I'm occasionally pulling a 4000# trailer....
Thanx, Jeff