It is a nice hotel with nice staff, decent restaurant (very surprised to find it empty empty, considering the food and prices) and amazing breakfast. The location is perfect for visiting the museums and it is also very close to the London underground.
When we were there, the ventilation was just being replaced, so we had to sleep with the windows open to the very busy Cromwell street. Surprisingly, on the 3rd floor, this was not an issue at all.