I booked a dinner for a group of friends who come from different cultures and who are all choosy (because they are all working in Hanoi at the moment) as well as so familiar with different good places around the town. It was quite stress for me as the beginning as this was an important dinner and I wished to make a different impression to them, of course I mean great impression. As the restaurant is not so spacey, they first placed us in the room and I did not like it. So I insisted the staff to move us to the open air areas. It was difficult to do so with our booking but the staff have managed it perfectly, without bothering other guests, and always kind and nice. Five star customer service, especially to Sabrina, love you :-)
All in all, I just repeat what others wrote alot here: extraordinary view (one side is the sparkling Thang Long bridge over the Hong River, one side is the miraculous Hoan Kiem lake and its surroundings); excellent service, great food, and because of all that, we have made four big bottles of good wines 'evaporated' :-D
You should definitely be there, and if during this beautiful autumn evenings, remember to book a table outside to enjoy cool atmosphere and marvellous view.