I've voted "not sure" as it won't bother me too much if a commentary track is missing. I rarely listen to them. They're either informative or tedious. Also it depends on the personalities giving them.
Good examples that I recall are;
The Evil Dead - anything with Bruce C basically.
Chasing Amy - when Jason Mewes wakes up halfway through and begins to introduce everyone.
The Beyond - Catriona MacColl and David Warbeck.
I listened to William Friedkin's for the Exorcist 2000 print and he mostly just describes exactly what we're watching
