I've heard about using NR -1 to prevent 'smudging' tendencies from in-camera noise reduction.
ISO 12800 is as good as ISO 3200 on 5Dmk2 is a bit of a stretch I think, but tech is constantly moving on... pics please!
you're right abt NR -1. Shadow tone -1 is also because the blacks are too black!
as for ISO, its just my impression becos the highest ISO which i can tolerate for my 5Dmk2 is 3200. while for X100s is 12800 after just a few casual shots. The best is still pictures to compare. I'll try to find time to compare the X100s, X-Pro1 and 5Dmk2. whatever the result, the X100s is definately a winner, besides pixel peeping.