I wasn't really talking about there being sonic differences. Nore really people walking around with a naked shell of armatures hanging out their ear. o_O TF10 have a weak spot where the nozzels glues onto the housing, we've several cases of them falling apart. I'm guessing UE900's weak spot will be there around the faceplate seal.
I was under the impression that the shell had only aesthetic purpose nothing more, meaning it was glue on top of already enclosed back, otherwise I see your point if that was not the case.