Like others below, I am hesitant to raise this place's public profile because it's so good and I'd rather keep it to myself! But, being unselfish, Mustafa and his staff would probably love to have more business right now because Luxor (and most of Egypt) are suffering from low tourism. There cannot be a better time to go!
We stayed for three nights around Easter 2012 and it was simply fantastic. We only called to book about four hours before we arrived and it was no problem for them to give us a twin room. We arrived quite late in the evening and our bags were carried to the room - once we'd been given a choice of two! Both twin rooms looked beautiful, with spacious queen-size beds, mosquito nets (not really needed) and en-suite shower and bathrooms.
The room we chose opened out on to the poolside, which had plenty of loungers and towels for you to use. The pool is not artificially heated, but it was warm enough without that anyway.
The staff were gentle, welcoming and always keen to be at your service - but not overly so. We were offered the chance to eat breakfast wherever we wanted in the hotel grounds - the garden, either of the rooftop lounge areas, or by the pool. We were given a nice selection of local breads, honey, jams, boiled eggs, pastries and meats each morning, along with fruit juice and bottled water.
The location is, admittedly, a little hard to find. When you get off the public ferry over the river (don't be tricked into hiring a boat for yourselves - it's a scam - use the big public boat that has two floors) turn left and keep walking. You will eventually find yourself walking along a dirt road, past one or two riverside restaurants and shops. Turn right after a couple of side streets and you'll walk past a laundry/ironing shop, follow the road around to the left and at the end of this street, you'll look to your left and there'll be a wooden gate (see pictures on this page and hotel website) where the hotel is located. It's a secret for a reason :) You'll be grateful you tried hard to find it once you arrive!