You have to make sure you are not imposing what you as a human would want, vs what a snake would want.
Most snakes want to stay hidden, and eat. On occasion they might want to mate. If you put a ball python in a giant pen, with lots of lighting and plants and stimulous, and hides. They stay in the hides. That's a major complaint of ball python owners to me, that the snake just sits in the hide all the time. That tells me that the snake prefers to stay hidden in a enclosed dark spot.
I've kept snakes in large and smaller tanks, set up with tons of hides, and with nearly none. I went to racks, because the snakes seem less stressed to me.
I don't disagree with giving a ball python a giant open enclosure.. but if the snake isn't eating, and roams around looking for a spot to hide in, then why would you WANT to stress the snake, just to make it live as if it had human wants?
I'll try to find the thread too.
Edit: here it is
http://www.ball-pythons.net/forums/s...ad.php?t=81034