Hmm... third sling thread this week. Maybe we should have a sex-dungeon forum topic?
Slings are fun to play with, and if they're easily adjustable, can make up for uncomfortable differences in partners height. If they're not adjustable, they can make it worse. But in the end, you are only touching each other with your dick, and I generally prefer a bit more tactile contact than that. Um... btw, if you have an overhead cable machine in your home gym setup, you can clip a climbing harness into it, load up the sled with the equivalent of the bottoms weight, and manipulate him in three dimensions. Just be careful about banging heads in close quarters.