Well I have been trying to learn CS5. The bristle brushes were and are a tad perplexing to me. But what may be helpful in restoring photos is to use the mixer brushes on the edges of hair in photos you are trying to restore. The mixer if adjusted properly will pick up the color of the hair and you can drag it away from the subject a tad to make a realistic looking edge.
I just thought I would put that out there. It looks like that will give a better result than smudging or using other brush types.
Sounds interesting. I don't have CS5 (I feel like I'm still learning CS4) but I'm fascinated with the content-aware fill. I'd be interested to hear how it works out in practice.
Tori