@nikonrumors The format isn’t the issue, I don’t care what the slot takes or uses just give us two slots just in case one fails, simple. Everything else about the camera is secondary.
@thatcatJJ Compact flash by Sandisk in a d810, the first one had been through a few shots but the second wasn’t old; it corrupted last week and is completely dead so used the backup. Personal choice but I’d rather be safe than sorry.