I love them both. It really depends on what kind of atmosphere you're looking for.
LeCellier is in a theme park. As a result, it's more crowded, more rushed, and more hectic. That said, the food is wonderful and the staff is great.
Yachtsman, because it's in a hotel, is more relaxed. The food is also wonderful, but the restaurant itself is more spacious, it's a little bit fancier, it's much more relaxed, and you can take your time without feeling like you missing out on something.
You really can't go wrong with either one.