CS5 Masking - Edging Out Fluid Mask?

I used to think Fluid Mask was needed to get great mask transitions. After watching this video, I think CS5 has caught up to FM (and maybe surpassed them) in many ways

http://tv.adobe.com/watch/the-russel...photoshop-cs5/

All the tutorials that I have seen so for for this feature isolate the subject from a very plain background and the results are exellent
I would like to see a demo where the subject was isolated from a complex background.
Have to agree though that this is one of the better tutorials.