I use synced collections a lot when I want to share selections of images with clients and collaborators. I think it's one of the killer feature of Lr. However I think it's missing the ability for the client to view just their favorited images. I often get asked from them if it's possible. It would be great to be able to see just the images selected for retouching from a shoot, to see if they work well together.
Is anything in the works or am I missing a way to do this?