Bass traps: Filled or open corner?

I have seen both done when researching online and wanted to know if it was worth while filling the back? What I mean by that is basically stacking up many "triangles" of the rigid fiberglass or rockwool to completely fill a corner VS making the panels that are ~2-4" thick with the airspace in the corner? Also, though not in the subject line, was curious. Would there be any reason not to use a combination of rockwool and fiberglass in a single panel?

IMHO: YES, it's worth it. More volume of wool means better basstrapping. Has it been tested? (panel vs chunks).. not that I can recall. A supperchunk (filled corner trap) is easier to build, atleast that's my experience. But I do not have a lot of hands-on/practical experience (yet). A filled corner is more expensive (more wool) I'm a huge suppachunk fan :)

SuperChunk! HA! Awesome name for it. Glad to hear that, I know I have seen the name put out there quite a few times, just never knew what it was. Thanx!