We only stayed for one night - but sorely wish we had stayed for longer! We had come from Marrakech and were generally more impressed with Essaouira but Riad Al Zahia vastly outshone the riad we stayed at in Marrakech.
It was extremely easy to find from the directions on the website - so we independantly made our way on foot through the Medina, without the need for a porter
We found the staff friendly and helpful and they assisted us with our onward transport, and as our departure was before breakfast - they prepared a tray with coffee, cakes and yoghurts to be left for us which set us up for the day.
All the rooms communal and sleeping accommodation were beautifully decorated, full of character, yet calming and conducive to relaxation. Even the Iman was musical and heartening with his Call To Prayer, compared to Marrakech!
If you're going to Essaouira, which I would recommend over Marrakech - you must stay at Riad Al Zahia!
Review from traveler, stayed March 2011, travelled with family