The bone marrow was really delicious - albeit just a tad bit over-salted in my personal opinion but still really good and worth getting! They give you a huge helping and its enough for 2-3 people.
In addition, the mussels are amazing. They come in a different variety of sauces and are soaked with flavor and have no 'fishy' taste as I've experienced with other mussels/seafood of this variety.
The atmosphere is very classy and refined but still hip and fun to be in. They have late night burger and food specials that are extremely cheap and reasonable despite being a high end resteraunt.