You have to judge a restaurant against what it tries to be, and what Il Mulino tries to be is an "experience". A very expensive experience. A very expensive experience with food that is only good, not great (with exceptions).
But Il Mulino does succeed is being an experience. The decor is elegant and "rich". The staff, for the most part, polished and proficient, but not fawning. You start off with complimentary breads including garlic bread, bruschetta, grilled zucchini, fabulous aged parmesan cheese. All this before you order. And you end the meal with complementary grappa. The meal is well paced, the clientele interesting, and the food "good enough".
Since the main course portions are more than adequate, and you are already half full from the freebies, you can probably skip the appetisers. Listen carefully to the long list of specials, recited at breakneak speed (interrupt if you need to), because a lot of the good stuff is here. The bronzini baked in salt is much like signature dishes in fine restarants in Spain and Italy -- spectacularly good. All of the pastas are good; don't order half portions as they are almost the same price as full portions. Some of the meat dishes are only ok.
The bill will be high -- about $100 a person with a glass of wine, tax, tip, and maybe a dessert and side dish. But if this is what you expected from Il Mulino, you will go away happy.