While my home desktop is 4 years old, i do have fast internet. It did not take long to download the 2.3 gigs of files for the upgrade, but it was the 3 step process afterwards that took some time. That was probably more to do with the processor and RAM. MS did a great job in keeping all my userid's, passwords and other settings exactly the same. Even my wallpaper was the same so when the process finally ended, you had to really look hard to notice the difference. Plus i think the performance improved.
I agree with you that Win 10 should have been the next step up from Win 7. The Metro interface is not all that great but it is much easier to deal with popping up from the Start button than the unintuitive ways of Win 8.x