I definitely prefer Salt. I like Crush (and it's very convenient to where I live), but I've never been wowed by the food like I've been at Salt. My favorite things at Crush have been their desserts, and even in that category, I greatly prefer Salt's incredible little doughnuts or mini delectable ice cream cones.
I enjoy the lobster mac and cheese at Crush. They also have a nice grapefruit crush drink. It is much easier to access, Salt is kind of small and out of the way.
Salt has a fun menu. I prefer the location of Crush, but I like the food at Salt a bit more. I feel that the menu is well-executed at Salt, plus they have some fantastic duck fat fries.
I am a big fan of Crush - have been there twice this year. I can remember having short ribs, salmon, and maybe rockfish (can't remember) - all were good. They also have a blueberry dessert that is fantastic. Unfortunately I still have never been to Salt, but I have only heard good things about it.