We heard of this hotel through Lonely Planet, and were we ever glad to have checked it out. The hotel has about a dozen suites, all named after famous Belgian painters and containing very high end appointments (Sky TV, marble bathrooms, etc). It's sumptuous to the point of decadence. Our room had two levels (the Suite Paulus). The bed was very good quality, room was quiet and warm.
The staff are very professional and courteous (which is to be expected at this level of cost). They recommended to us a number of good restaurants in the immediate area.
The location is quite prime as well. About two blocks from the train station and just up the street from the Grand Place. The very best of the Old Town of Brussels lies at Le Dixseptieme's doorstep.
A breakfast (both continental and hot) was included and pretty good.
The hotel's both quite popular and possessing of minimal stock, so reservations are a must. Our rate for two adults was $240 (US) a night.
www.ledixseptieme.be