Based on demo videos I have watched, I'd say a pair of S1's would be dandy with OR without the DOCK. Adding tablets just makes it even better and using the CONTROL app on a 3rd tablet adds even more. Does the DOCK add more to all that? Sure. Do you NEED it? Totally up to you
(besides, if you never had the DOCK, would you even miss it??). Check out some of the youtube videos on the S1(I have and it looks plenty capable without the DOCK to me)