I have both -- I really like both of them!
The Crux is a little beefier, with a stockier handle that provides for a more secure grip. The grind isn't quite as aggressive, but it is definitely thin behind the edge. Makes for a nice EDC that is certainly capable of some harder use tasks.
The Dao has an excellent blade shape in my opinion, but I am partial to the modified wharncliffe/Insingo-esque blade shape. The Dao is a bit better suited to finer tasks in my opinion, and essentially replaced my Small Sebenza in my carry rotation.
Another option to consider is the Buc -- the blade is a bit more "out there" than the Dao, but the added blade weight makes for a nicer deployment and a stabby but sturdy blade tip.
And yet another option to consider is the Keen (not FF, but still MD/WE) -- a simple thing executed well. Can't go wrong with that.
I really think these MD/FF/WE knives are among the best value buys in the production knife world.