This restaurant is resting on its laurels. We should have been tipped off by the plethora of movie star photos which line the walls. While one of its claims to fame is inspiring Julia Childs to a career, I seriously doubt the current version would do the same. It is an expensive restaurant and we expected first class service and food. The service was lacking. There were only 2 waiters in our dining room which resulted in an understaffed situation. Yes I know, slow service is typically good service in France. However, being ignored for 40 minutes is not good service. Furthermore, the couple at the table next to us (who were French nationals) had the same problem - to the point where the gentleman got up from the table and expressed his feelings to the staff. The entrees and plat principals were pedestrian, good but far from outstanding. On top of all this, we were charged for an extra glass of wine. But at that point , I just paid the bill to be done and we left. If you are looking for a superior meal in Rouen, try Auberge St. MaClou which is outstanding with first class service. As for La Coronne, it’s just not worth 300 euro, not even close.
You're confirming what most of us in this forum are already aware of -- if you look around the interwebs beyond insta-influencers you will find this same impression. I always tell inquirers that La C is for the cruiseline crowds.
The trendy but actually good spot in Rouen is 6eme sens, as several of us here have mentioned.
Also take a look at Simone.
For everyday local dining, see my review here on the forum of Pascaline.