In my experience with WD elements drives, its the WD Green drives they put in the enclosure.
I can only speak from my personal experience with the element (and I'm not trying to discourage you from buying) but I had a WD elements 1TB just stop working one day. Put the HD in my PC to try and recover some data, but there was nothing I could do.
If you show me the exact model you are looking at (as there are a few varieties) I can help you with some more information.