The didymos looks more secure for bigger babies. I like the look of the peanut shell also, but I like the adjustability of the ring slings. As for the moby, it looks secure also, but I'm afraid I'd get tied up in knots

or get to hot. We're headed into summer, when baby gets here, in Missouri. It gets so muggy. I don't know the moby, ect. look better for my back.