Slept like a charm using my Incubator underquilt on a Speer Hammock. It was 17 degrees out and I stayed warm. The Incubator worked as well as my Winter Yeti.I like both underquilts equally. But my favorite underquilt is still the Speer Pea Pod. I can lay in the deepness of the hammock body and look at the night time stars and clouds moving in the sky.