Something I wanted to share. This morning my Z1 upgraded to Z2, with MK6034GAX harddrive, the unit showed a message that it "Could not use HDD". The temp this morning was about 15-20 below 0 in Wisconsin.
Moral of the story is this drive doesn't handle the cold as well as the stock. I know this is pointed out in the specs of the two, just wanted to confirm.
Anyway, it worked fine after a few minutes with the heater on.