i would go with the camel ride as it is more comfortable.you can enjoy your ride without getting a painful back.while horse keeps you jumping all the time it gives me a real back ache.i would prefer slow moving camel.
I think for the rareness and enjoyment, I would like to ride on a camel since it is rare on our country and it can journey beyond the desert without getting dehydrated. So I would go for Camels.