Peg, I understood about the kids in Kids, but there were elements about them in groups that I think was way off--too many of them were too comfortable with each other. I think Clark was projecting a Gaugin-like thing onto them--something you didn't see in Gummo.Some actors seem t.v. sized. It seemed odd to me in Saving Private Ryan, here we are in war-torn France, and hey--there's Ted Danson.
Some actors commit more to bigger-than-life, cartoony roles. Tim Curry--he just doesn't look or act right in real-ish drama. Michelle Pfieffer should try more over-sized roles; Catwoman was the only thing I've seen where it didn't feel like she was turning in her work for a grade. Pretty good sometimes, but tiring.
Malkovitch is the only actor I can think of who I can see "acting" and doing a good job of it, even showing off at it, but it doesn't intrude, just adds a playing tension. That's why he'd be good in a Nabokov story. The Luzhin Defense with John Turturro was okay, but lacked that sense of play.