I've just upgraded my XenForo from Beta 3 to Beta 4.
I'm also upgrading my vBulletin 4.0.8 to 4.1.0 PL1.
Now, the difference between those 2 sentenses is that one is in the past and one is still going on (continious).
I've started the upgrade at the exact same time, and my XenForo Upgrade is done for +/- 10 minutes now, while my vBulletin is still stuck at 98%, for over 5 minutes.
My XenForo showed a nice little phrase that said "We are currently upgrading our forums".
In vB, I had to do that all by myself
I'll keep ya up to date on what errors vBulletin brings
As for XenForo, I had one little error, but that was fixed by Mike. Exellent support guys!
Btw: Still stuck at 98%