Basically the difference is elsewhere. The ISO made through Windows Upgrade Assistant only consists Windows Pro image in install.esd/install.esd.decrypt; thus it is slightly smaller.
That's true. My point is else: If you couldn't compare with the official MS, you could not know what you're getting! I wouldn't take that risk special if I do some setup etc. for not my own hardware/system! Is just a question of security!
Fully understand considering I'm a lurker and do not have many posts here. Don't worry If anyone has trouble, do post here / PM me. Over the 10k+ downloads and climbing, no one has reported any issues. These ISOs have been out there for over 6 months.