OK, so I know most people wouldn't apply for either in a million years but what if you were compelled to?
One has a prize of £1 million, the other £70,000.
In one you have to eat bugs and worms, the other drink cider.
One means camping out in the open, the other living in a fairly cozy house.
On Survivor you can hide from the cameras, on BB you can't (not even in the showers or toilet).
BB means being judged by the viewers, Survivor means being judged by your fellow competitors.
I think I would probably choose Survivor. I don't think I could handle the experience of being filmed 24 hours a day and then being judged by the public.