I've tested this now almost every which way -- both as a VM and on a Real machine (several in fact).
It's a Good OS but I have 4 Showstoppers and a BIG niggle before I can use this as a main OS. (Note I use a decent LAN with servers so as a single Home machine the problems might not seem too problematical).
1) Network sharing across machines -- mega problems with Linux -- I can READ LINUX from Windows but I can't get SAMBA shares to work properly from the LINUX servers. Ping works fine but gives a totally different address (59.x....) from the LAN address (192.X etc) whether I use Bridged or NAT working on a VM or even as a real machine --probably something with DNS or IP translations. IPV6 or IPV4 makes no difference. I'm not enough of a Network guy to bother spending a huge amount of time on this -- if I can't make it work even after about a days work of research (and I've been quite busy too on the W10 Forum --thanks to all who replied to posts) then I'll wait until nearer an RC.
2) Media servers won't connect at all -- I use these a lot so no good here. I need the ANDROID phones to be able to connect to the media servers. Windows Server not working properly.
3) Touch doesn't work properly so I can't really use Touch devices.
4) Language packs for my language are not yet available -- (that's also a sort of "niggle" rather than a mega problem though).
(Another partial niggle which I'm sure will be addressed before RC (Release Candidate) is that the start menu's text can't be enlarged - but at least full marks to Ms for bringing it back). I'm glad custom toolbars still work though.
The BIG niggle is the whole issue with the Ms account -- convert your user to an Ms account either intentionally or by accident then you have a whole lot of issues with LAN's and user accounts. You can of course avoid this issue by not creating an MS account in the first place - but if you DO create one and want to revert later --it's bad news.
For a SINGLE HOME machine Ms have done a great job and I KNOW it's alpha or pre-beta software - but the whole Networking mess needs to be worked on big time before it's "Lan Friendly" especially with a mix of Windows and Non-Windows devices in the network.
So Thanks everybody again for replies.
I'll keep the odd VM around for occasional testing as problems get sorted - but currently for me not ready for prime time yet.