I just did the upgrade and it took no time at all.
Actually, I took your word that it would take a while, so I went to cook a nice dinner ad glanced across about 20 minutes later to see the installation asking for a reboot, then before I knew it, it was completely installed.
Really struggling to see the sense/logic behind a desktop without a start menu, though.
Yes, I hardly use the start menu in the real world - most of the time I use it simply to use the search bar to type in what I want, be it the application or a shortcut to something like mstsc, cmd etc.
But living completely without it? Don't get me wrong, the new interface and it's possibilities are great, but you're not honestly expecting people to know exactly what's installed on their system and to use the search to find the application they need, are you?
It's either that, or 2-3 clicks/gestures more than it should be.
Interesting operating system, I'm undecided so far, but I can say that it does feel quicker/snappier than Windows 7, which itself was sharper than Vista and XP, so Microsoft are heading in the right direction in that regard.