I use them as scheme runners...they can double walk and get a free Defensive, so they can help out with stuff like leave your mark or inspection. Bravado is also pretty good as you discard a card and then pick a suit to add, not just the suit that was discarded. So they can take 2 Ml attacks and toss a low card for a mask on the 2nd, to push 3" which gets them out of all but the bigger engagement ranges of enemies. Cast-offs can be used to double McCabe's Take This range...toss an upgrade on a wastrel in 10", push him 4" then cast off on a target in 6", which then gives the wastrel a trigger (which you can pick if you discarded to a card beforehand, since there's a duel involved in cast-offs). This can lead to a ranged attack with a blast, a Ml which hands out slow (which McCabe and Sidir can exploit), a self heal or a 12" teleport to a scheme marker.
I find a lot lot of use for them in McCabe crews obviously, but I've also used them in a Lucius list. Bravado really shines with Lynch though, because you can toss an ace, pick your trigger for cast-offs (which only the heal other model really works in a Lynch crew), then pick it back up. All in all, for a 4 point model they're pretty good.