You can almost carry any of the massdrop × FF knives in a gentleman's carry situation. Even the new mordax looks very classy in person (and I got the bright blue one!)
That said of the four I own (the Crux, Gent Select CF, Buc, and now Mordax) my favorite to carry is the Crux. I have kept it in my EDC rotation and also carried it in formal situations.
I believe the Gent is perfect for most Formal situations while the Crux is a mix of utility and class. The Buc is more of a collector piece than a user knife imo. But that's also why they offer a user friendly version of it in the Dao (one I must get for this reason).
That said, after only owning it for two days, I can tell you that the Mordax is probably the best of the bunch.
It's basically a thinned out and lighter but larger Crux with the smoothest button lock I have ever seen and a better shaped finger choil (similar to the Buc and Dao).
I believe that DROP is absolutely killing it with these collabs. Keep it up.