I did enjoy our stay in the hotel (November 2009).
The room was big enough, the swimmimg pool too.
The food was good and the prices were reasonnable. As a matter of fact, this the Only hotel all over Vietnam where we always had our meals. No use to go outside because it was good !
I do recommend this hotel. Be just be awre that the pictures are a bit nicer according to the reality. :o)
Thanh Noi hotel is interesting. It has excellent location being right in the imperial city, and next to the forbidden palace. However it is also a cab / bike ride into town for meals and shopping.
The hotel is on a nice property with excellent swimming pool, and great restaurant setting. Drawbacks are the rooms themselves. They were adequate in all ways, except they were very damp and smelled musty. If you can handle the dampness, and want to be near the citadel this is an excellent hotel.