I'm thinking of picking up an XL4. I currently have a stream and a premier. Would the two Tivo's simply work independently with the ability to transfer content show by show or is there an additional folder that would allow you to easily see what's on the other DVR? If there is deeper integration I would assume it's NOT so robust that either tivo sees that it has X amount of tuners based on the number and type of Tivo's. I.E. I try to start a recording on a tivo with both tuners recording and it seamlessly uses a tuner on the other Tivo. How does the stream interact with multiple Tivo's? Does it work with both well or is "setup" required when you want to switch between them.