We stayed in Riad Houdou for a few nights in July. The Riad is located in the middle of the Medina (old town), although it's not hard to get there (it's very close to place Moukef, where taxis can still stop). They have a pick up service to and from the airport, which is slightly more expensive than a taxi, but worth it.
The riad is small but very well maintained, the rooms are well decorated, and the place is very quiet, on a side street which separates it from the bustle of some of the streets in the medina. The atmosfere is very relaxed and homely.
The staff is excelent, very very friendly and efficient, and the two french owners (Didier and Eric) are extremelly helpful, friendly and attentive.
Breakfast is very good, with plenty of choices, and dinner is even better (it's not included in the accomodation, but it's well worth the price, I highly recommend it).
Our room was very nice, with a small balcony for ourselves, but the downside was the fact that it was on the top floor, and therefore very hot during the day (it is air conditioned, but Marrakesh is very warm in the summer months).
I highly recommend this riad, as it has excelent value for money, the location is great to explore the medina, and we felt extremelly welcome throughout.