I use spider guard a lot for triangle and armbar setups. I've been trying to work butterfly guard more, but our class really hasn't touched on that one much, so I'm just going by what I can get the blue's and purple belts to show me. However we do do a lot of spider guard, X, and De la Riva stuff. I try to work open guard as much as possible because Im told by a lot of people that closed guard is bad for MMA.
Speaking of De La Riva, we have one of his black belts comming to do a seminar at our club this weekend.