I'm currently having a play around with Speedgrade (which I'm loving) and using Alexis Van Hurkman's excellent book. All nice and easy to use but run up against an oddity when it comes to saving masks.
Now, this may be something that has changed between CS6 (which the book is for) and CC. But it says that to save a mask in the "/settings/masks" tab you press Command-P on a Mac. But this seems to save the look rather than just the mask.