Hi,
I have been using Gepetto in some "Station" settings and aside from the limitations of the characters, (i.e one generic female, one generic male) have found it easy to use, and with a bit of creativity can really add something to a scene.
The movement is naturalistic and doesn't, if used sparingly, have a detrimental effect on rendering times. The interface can get a bit clunky with lots of bodies, but no more so than when manipulating any other scene that has large numbers of discrete objects.
I used vertical offsets of cameras to achieve multi level animated people. Bit of a long winded way of doing things but very effective.
I hope this makes it into Max.
Rgds
Chris