We rented the whole Ryad for a weekend (6 rooms) and it was overall a very good experience. Very clean, sophisticated decoration (over-ornated in my opinion, but, well, this is Marocco), very professional (and numerous) service, and a fantastic terrace (although we couldn't enjoy it due to rainy weather). Having a shower in the top-floor room was a bit of a challenge due to low pressure and small space, but it didn't seem to be the case in the rest of the rooms.
Breakfast is excellent and having dinner in the hotel is worth it (you have to tell the staff in advance and be sure to clarify beforehand which drinks are going to be included in the price).
On the other hand, I wouldn't advise this place to anybody not in good physical shape, given that the hotel is located up a hill from the medina and city center and that the stairs are very steep (no lift).
Otherwise, be advised that there's a 50% mark-up on taxi ordered by the hotel on airport transport compared to official prices and, as in any other hotel, compare prices for excursions, etc, that you are offered by the hotel. Anyway, at Dar Sultan, they aren't selling aggressively extra services.
There is no Internet.

From the outset you are warmly welcomed into this very intimate setting. Everything is done with the greatest of care and taste. The rooms are lovely, the soaps smell wonderful. Do not miss having dinner at the Riad as you will not eat better anywhere else (perhaps even in all of Morocco).

The experience at the Riad made the trip to Tangiers that much more special. A wonderful gem.

a wonderful riad, full of character and lovely staff - stayed in room charf on the top floor which is definately to be recommended as it has amazing views of the city and the sea from a truly wonderful and private terrace - room is small but the views more than make up for it - difficult to leave the terrace!!!

The Dar Sultan has obviously been upgraded since the bad reviews in 2007 or the recent one about a 2007 stay.. It was sparkling clean and, freshly painted; the beds in all 3 rooms were very comfortable;the bathrooms clean (if small) with plenty of towels, the views from the roof terrace were superb, the breakfasts (delivered to the terrace) were freshly cooked, different each day and delicious and the trays of sweetmeats, Easter eggs and fruits left in the room every day were far too tempting. The service was polite, friendly and helpful and the dinner we had there one night was the best meal we ate in Tangier. But best of all was the kindness of M.Durand, the owner, who, when he discovered that bad weather had causded the cancellation of our catamaran ferry to Spain, ran us to the port in his own car to negotiate with the boat companies to allow us to change our tickets and get across in time to catch our plane. Would stay there again with pleasure. Top marks.