It would be great if you could use the paint tool on families that have been placed in a model. I find a lot of times I would like to try a different material or color for an element of a family. The paint tool seems like it would be an easy way to do this but unfortunately it won't work with families in a model. It is a pain to have to go back into the family editor to change the material of a specific piece of the family

Yes, ideally every family would have its components with specific parametric materials or broken down by a dozen categories of object style, but we all know that this isn't the case. I haven't thought it completely through - maybe there is a reason why this would be a bad idea, but I has not occurred to me yet.