Dear Linda,
I very much like the overall design of Brad's portrait. It is a simple and successsful value scheme, and you have really handled this beautifully. I think your painting shows a great deal of sensitivity for edge and color transitions, something I work on every day myself.
For my personal persuasions, yes, I think there is too much room on the top
I think it is hard to have lots of room at the top, although I have seen some painters make it signature, beautifully designed approach. Peggy Baumgaertner uses a rule of thumb - not cast in stone!- to leave a forehead's length between the frame and the top of the silhouette.
I'd love to hear about the Yes Canvas. I am sort of lazy so I would probably avoid buying a canvas that needs work... even better, if you are attending the November Portrait Artists of Arizona meeting, would you bring the painting?