I haven't been to Rose and Crown.
I thought Les Chefs was really subpar. The food was just eh, I can make better stuff at home. The service was just...eh as well. Not somewhere I have any desire to return to.
Le Cellier was good. The steaks were just your average Outback/Longhorn kind of quality. I really enjoyed all the other items I've tried there though, and would return for those (Cheese Soup, Pretzel Bread, Tomato Stack, and Maple Creme Brulee). The server I had at Le Cellier was very good - Jess from Yellowknife. Sweet girl! Le Cellier is also a a bit quiter and not as boisterous as Les Chefs. You'll probably be able to hear each other better in there.
So that's why I voted for Le Cellier.