Be sure to check the firmware version on your B9 units when you receive them. Mine actually is using a firmware from December 3rd 2015. The newest firmware is from December 11 2015. Not sure if they added anything or not but I'm updating mine right now.
repeated many times, ain't broken don't fix it
B8 was 3rd but upgrade to 11th dec fw, no difference imo.
my "B9" comes with 3rd dec fw too & 1 of it has some brownish marks on the female pcie on 2 of the blades heh. very little dust on it. looks new to most but with careful inspection seems like it's B8.
well at least it works well before & prolly lesser chance of RMA. i'm ok with it as long as it's acceptable.