What you fail to understand is I'm not having any issues with Win10. And I chose not to use a VM, period. I don't see the need and I don't plan on using one now or in the future.Maybe you should! When first having the TP on a VM that was set up there to avoid the problem previously seen with the 7/8 Customer Preview dual boot set up where both installations had to be replaced! At first 8 was added into the 7 BCD as a boot option until the disk errors seen as a result of the dual boot across two OS drives trashed both! The PC Refresh option followed a clean install of 7 also resulted in both crashing again until 8 was simply gone for good!
I missed trying 8.1 out in any form when having been side tracked a bit for some other reasons and then checked out the TP build that was available in January to put that on a VM before going through that other situation all over again! This time however noting nothing had changed as far as hardwares! 10 went on as smooth as silk BUT couldn;t added as a new boot option in the 7 BCD store from being three versions newer! 7 was made a 10 BCD there instead.
The initial upgrade installs on the main build but not the second build accessed remotely as well as the laptop upgraded both saw what best described as a travesty! Both first upgrades were trash! On the main build during the first week the second upgrade to repair the first went unactivated due to bogged down servers. The following weekend then ended like right this time of night on a sunday for the first clean install that activated within a day's time on it's own! Now the activation is seen before you even see the desktop fully loaded automatically if 10 or a previous version being upgraded over saw activation there.
Bot the Home and Pro 10586 editions saw activation on VMs but with the Home VM on the second machine there. 7 product keys were used while the Threshold 2 wouldn't accept any either from already in use or requiring a 10 key instead of any previous version's The VM however is how to check up on things fast without the need to change any physical 10 install since you can run it on any edition or version of Windows from 7 up! I doubt you could even get 10 to run on the Virtual PC 2007 option used on Vista even for 8 or 8.1.
What each upgrade does unlike seeing an SP go on after a year or so of waiting is see an updated build with a number of fixes already tended to but with the more frequent install at this time until next summer since everybody seems to be running the RC1, RC2 stages you would have been seeing with an older version but now are seeing these latter builds out on new machines! You can be sure while the first inventories saw the 10240 other new machines coming ouf for this time of year most likely will be seeing the Th2 build instead and next year see TH3 or TH4 by next summer provided more Threshold builds come out.