I have limited time on the debonair but the DPS is my favorite in line shock by far. Overall feel and Small Bump is real close to the float X, the almost-full lockout feature is incredible, just about gives me a hardtail going up those long fire roads.
A shock is definitely next on the list for this bike. I've always used and loved the monarch but if the DPS is as good as you're saying then maybe i'll have to give it a try! I have only heard good things, and the lack of a reservoir would be nice for water bottle reasons. We dont have long enough descents in Maine to necessitate a reservoir.