I’m using the Attach functionality of the Outliner to attach windows, doors, and set dressing to a “parent” building mesh for organization. So far it works great, but I’ve noticed that the undo operation will expand every hierarchy in the Outliner. Something as simple as moving a light, one that’s not attached to anything, and pressing Undo, will repro the issue.
As a side note, the Outliner is great so far and I’d love to see its functions expanded on. Maybe add a generic null or group node (a workaround I’m using now is using a Note actor) and allow child actors to inherit visibility from their parent. Also, maybe a middle-mouse click-drag to re-order actors in the list. This functionality, coupled with the Layers palette, would match a lot of the power and scene management of Maya.