No I have not played with w8 spaces as of yet, I have fired up a couple of the beta's - and to be honest the UI was so off putting I have not bothered to dig much deeper. Because I can tell you this for sure, if there is no way to use the standard desktop - your not going to see many companies move to this version any time soon.
Most enterprises don't move their users until sp1 of new OS anyway, sure you will have a few beta testers in IT dept, etc. But not a major move - you would not believe the issues users have with just the simple office ribbon when that changed. Changing the UI, yeah companies are not going to like that at all! So got plenty of time to get up to speed with it. Not like its going to be mainstream for months and months, if not years after it releases.
**** lots of companies are still on XP
As to " I don't have unRaid running with a Parity drive. " What?? You meant "cache" drive right - I don't think its possible to run unraid without the parity drive?? If so please point this out!