Quote Originally Posted by Malamasala View Post
The memory usage would be the same as now. The real reason is that they wanted an easy solution to make sure a 2 piece item (head + body for example) would always be glamoured to another 2 piece item. Instead of having multiple checks on vanity slots for if head and body are changed etc. they just forced you to do the actions on the gear itself and the gear keeps track of what you can and can't do.

Had they never made those awful two piece armors, the good vanity system would probably have been implemented. With reservation for SE maybe favoring crafting updates over design.
No, it wouldn't be. The client would have to keep track of both sets, which is more memory used.