The relatively new Northwest terminal at Detroit, Terminal A, is very nice, but it doesn't have a high-end restaurant. Terminal C at Newark, in contrast, has Gallagher's Steak, which is a very nice option to have. But Terminal A does have a Westin attached with its own restaurant, Dema. You have to go out of security, but it doesn't take too long to get back in.
I had soup, salad, and osso buco. I was a little disappointed with the food---it was OK but not outstanding. The osso buco was tender but the sauce on it was a little overpowering. The accompanying vegetables were only partially cooked. I know it is a trend to serve harder vegetables, but I agree with Julia Child, who believed that vegetables should be served soft so that they can be digested. I think that's a particularly good rule when you're about to get on a plane. But the atmosphere is very nice and the service is good. It does make a nice break in the middle of a trip.