>- SanDisk 128GB Class 10, Extreme SDXC UHS-I 45MBps
I put that one in my D800 and have used it as a backup (i.e. in continual backup mode) from the beginning. I use a CF card as primary, because they are more pricey and you want the backup to be bigger.
It's worked fine through (just checked last night) about 24,000 shots.
I would suggest only buying SanDisk and Lexar based on reading about problems (and I stick to Sandisk after a bad Lexar experience -- but any given card can fail; I just happen to never have had a Sandisk fail).