One column installed, and it is only 1/8" from plumb on one axis; easily shimmed. The other five holes are drilled also, and I still haven't decided the best way to compensate for the 5/8" elevation difference. Guess I'll sleep on it.
And some great news, I found that I do not own a 15/16" socket, which means I get to buy one, or a set. I love buying tools, more than making holes in concrete.
Oh yeah, the concrete was 4 1/2" to 5 inches deep. Perfect.