I kicked off Windows update in the background and it chugged away with no prompting. I will admit this took a while but only because the ISO I have is Windows 10 RTM from 2015. It would likely have been quicker with a more up-to-date ISO with a later build.
The thing is it all depends on the hardware. If you're using more esoteric kit then you're likely to have a few more speedbumps regardless of OS.