Yes, I use workspaces to separate things (they are called _work_ _spaces_ for a reason). Most times by task, but sometimes simply because there is not enough space to hold all the required windows to complete one task open at the same time (yes, some of us actually use more than _one_ window at one time). The old MS Windows paradigm of minimise/raise is rather messy compared to seeing _everything_ in the workspace switcher and going there with one click (i.e. most times, no window is behind anything).
Static nature of workspaces (which to Gnome developer's credit has been reintroduced) is essential for visual orientation. If you read that paper by Nielsen that I pointed to, you'll see that he talks about "glancing" being superior to "switching", because you don't really have to do anything other than raise your eyes to do it. That is what workspace switcher is for, window thumbnails included.
Gnome 3 has zero visibility. That is problem number one. Gnome 3 needs two view switches for every workspace change (using GUI). That's problem number two.
Don't get me wrong. I use "activities overview" on my Android phone all the time, because there is no space to put everything on the "desktop" there. Not so on my computer. So, I don't see why I should be RFC1925(6)-ed all the time...