Jeff,
My first ribs on a smoker were good also - I put up the pop-up gazebo in the yard to cover the WSM while it was in action and I stayed dry the whole time. It was the way to go. The first thing I learned was that I "over rubbed" the ribs - I got a little extra zealous and piled the rub on instead of the "dusting" that would have been better. So, they were a little spicy, but still better than any that I have done on my Genesis Silver (a thick bark, anyway!). I think one thing I will do is cut down on the Cayenne - I like a little sweet over the heat.
All in all - a good first outing - temp control was pretty much like everyone has been saying. Thanks for all the good info from everyone on this board.