My vote would be for dual affiliations with II and RCI both - that way the members have access to Hilton and the Manhattan Club through RCI and the Marriotts, Hyatt, the Royals, and Westin/Sheraton via II.
Or a mini exchange network between the name brand vacation clubs would be nice.

Any name brand product that made it into RCI or II's exchange pool after the name brand clubs got first crack at it would be highly valued.