Yes I could, but by that I can only listen to CDs and not enjoy the fantastic comfort of the C15.
Not true, as far as I understand.
With Control:PC/Mac running, and the Prime plugged into the computer with USB, Control:PC/Mac will appear as a zone (or two) in the iPad app. I assume it's the same with the Control:15.
So you can sit with your Prime and your Control:15 and enjoy your Sooloos system to the full, with apodizing from the Prime and the full control interface of the Control:15.
(If you want the Prime some distance away from the computer you may need some messing with USB cables and hubs, but Joel's suggestion of a �200 PC would solve that problem quite easily as well.)