Whoopie slings are far superior for the following reasons:

1. They’re easy and fun to make.
2. You get to say “Whoopie” a lot - even if only in your own head!
3. You can use small sticks for toggles and watch other people’s eyes bulge when they think you’re going to support your whole weight on them.

As for useability and practicality, the differences are probably so small that it all comes down to personal preference.