I've had both and the Butterfly was more comfortable than the Damselfly. I did find that it was too wide in the back to be able to get off the back easily for more downhill technical riding and short in the front for climbing. I ended up with a Wylder Callisto saddle and its a happy medium between the previous two. I'm not sure if you're looking for a road bike or mountain bike saddle but my perspective is coming from a mountain bike riding view so, the "getting off the back" may not even be an issue for you. The Butterfly has definitely been one of the most comfortable saddles I've sat on though.

Good luck in your search! Its hard making the bum happy sometimes

Kristina