I have a large Citadel and it is a hand filling, durable cutting beast. I believe that it rivals any heavy duty Spyderco that I've used and it is indeed a work horse. The blade shape is useful for utility as well as its intended purpose as a backup weapon.
I would really like to see Spyderco come out with a non-auto version of the Citadel. I'd bet that one with a FRN or better handle ,a different lock, larger opening hole and other more main stream touches would make it a popular model .