For me it's almost always blade up on the bench. Reasong being that if I have the blade down and someone wants to pass by (and some benches are really narrow) I always have to check that my blade is not in the way. Dont' know why but when it's blade down I will always have it pointing foward, so this is annoying.
If it's blade up, sure, it can also point towards the ice but at least it's on the height of the walking person's head and he can duck easier.
Besides that it's a more natural position to me when I grab it with both hands once I get back onto the ice.