Thanks to everyone for responding!
We went with Mill's Tavern (or Mills Tavern?) for dinner, and it was a very good meal. We had an early reservation (6 p.m.), a lousy table (which I expected, given we called the night before for a reservation), and a green waiter.
For starters, we had raw oysters and littlenecks, and the king crab cocktail. The crab came with a ponzu sauce I didn't care for, but I just used the cocktail sauce from the oysters. I couldn't eat the shellfish (pregnant), but husband enjoyed them.
I had a cooked littleneck appetizer (my husband had salad) and it was probably my favorite of the night. (I can't remember the exact presentation, and the menu's not online.) The littlenecks were flavorful and the broth was perfect for the dipping of crusty bread.
My husband went with the delmonico, and I chose the venison. Both were fabulous. The venison was perfectly cooked. The allegedly garlic mashed potatoes were a disappointment, as there was no garlic that I could tell.
We chose apple crisp and chocolate mousse cake for dessert, nothing spectacular, but both were very good.
The waiter was new and stumbled a bit at reciting the specials ... first he told us everything on the menu was available and then at the end said there was no partridge ... forgot to prompt us on ordering sides on the steak. ... not a big deal, I'm just sharing all my thoughts about the meal.
As a former editor who handled food and wine articles for a large magazine (I am not qualified to be a food critic) I often notice that the hallmarks of great restaurants are small touches. Mills Tavern has the pacing of a great meal down pat (ours took two hours), a strong menu and a lovely venue.