My husband has the Catalyst and loves it. It will really boil down to what seasons you want to use it in and how much gear you have/want to bring with you each trip. The Circuit did a great job for me on the Appalachian Trail. I felt I had enough room for my needs. Good luck on the decision.

thanks, this was a detailed and comprehensive overview of the circuit. much appreciated!

Nice overview. Deciding between it and the Catalyst.

Man, I'd love to see a comparison video between the Circuit and Catalyst.

In these reviews I am always wanting to see the thing being worn not just shown.