OK, have been upgrading the Win10 1803 from the 1st May on into 13 machines with the automatic loading/install, few Pro most Home, as well as few Desktops most Laptops, and the most even on remote control, without any significant problems.
The 12th, a Desktop with Home did have an issue with error 0x80070003 in the end of the process after some 3-4hrs, a sigh …, but was cleared up soon quite easily with the Windows Update Troubleshooting procedure.
So, I anyway see this 1803 upgrade already a very reliable and ripe one, compared with the previous four, looked in backwards order, had been having more and more problems, and now already much less, which is quite natural on development process.
Of course there should be taken in consideration, that these machines have been quite standard office/home configurations, but in all there is in question 100's of mill.'s machines, with different configurations and devices and ageing uncompatible hardware and software components, as seen e.g. with the January 2018 routine update catastrophal case, locking 10's or 100's of thousands if not even mill.'s of machines already just after pushing the power button, due to the update addressed to the newer processor techniques, but was of course cleared here and there somehow, myself forced to re-install 3 machines totally from scratch …… (and guess who was willing to pay for the work, got just some really minimal compensation for any of those …&hellip
OK, now I have some 10 machines more to be upgraded, of which one Intel i7 Desktop on video production didn't even accept the 1709 upgrade at all despite several 3-4hrs trials and other life-saving procedures ... so, there is at least that one big challenge with 1703 left in the queue …
The others are expected to get upgraded smoothly as these 12 plus 1 sightly problematic have been showing fluency, but you never know …
So, the final verdict from me -> this 1803 upgrade is already a very reliable and ripe one on quite standard cases, but with more and more specialities and ageing, probability for problems will increase and could be expected!