This is the first update I have encountered where I ran into problems. I didn't reach the "get stuck at x%" mark. It would progress along (highest achieved: 41%) and then outright lock up my computer. Three times in a row this happened, and I couldn't for the life of me figure out why. I finally got around it by rebooting into safe mode (with networking) and updating it that way.
Hrmm...might be worth a shot at this point for me to try the same route you did. If it works for me, I'll drop back in to say so.