I did it. Got it on the first try. It's my wife's phone and I'll admit while I've been flashing phones for a while (since Winmo 6.something), I've never fully understood everything I do. It probably didn't need to be done but I did it when VZ was trying to push the ICS update and it kept failing. I thought maybe S-Off would somehow miraculously make it work. It didn't. But hey, it's S-Off now.
Is your bootloader locked or unlocked? If its unlocked, s-off or not, you can't get an upgrade. If your having that many problems, I would just flash the ruu. It wipes the phone, but you'll have fewer problems.