I would also choose YS. I've dined at both - when I went to Le Cellier my DH and I felt like we were sitting on top of the table right next to us. It was very loud and crowded and even though we enjoyed the Cheddar Cheese soup and Pretzel bread - the rest of the meal, including the steaks, was not great.
At YS, the tables are little more spacious and the service was excellent. And you can't beat the aged steaks there!