I've ran the install and upgraded the RAM 3 times already(for me, wife, and brother), and the worst part I can say now is the wait time.
First time I ran the install i was getting "can't find mach_kernel" which was caused by the iso image I created on my win 7 machine. After going back to square one and "properly" restoring the SL dvd on a MAC the installs finish with no problems.
I think most of the errors here have to do with the middle men in the install (the user and USB sticks). Like I said, I ran the install flawlessly on 3 different 10v's, a passion purple, obsidian black, and nickelodeon white, to be specific :-)