Great experience with guide Lyazid. We initially booked a 30-minute quad motorbike tour but ended up going back three times for a total of two hours. In conclusion, two hours is the best. You get to explore more and, most importantly, enjoy a break at Youssef Agafay's place. The experience was fantastic, with an exceptional meal (reservations required) overlooking the dunes and the sunset. In short, you should definitely try it!