This is just my experience, so take it for what it's worth. When I diet, I diet hard... mostly to make up tha difference in my lack of cardio. Over tha past year or so I've experimented with various protein type and forms. Due to my job title and responsibilites I've recieved copious amounts of powdered proteins and tested each with my specific training regimen and diet. In fact, I've gone as far as went several days / weeks consuming nothing but powder and nuts out of my own person conviction. I've used casein to replicate tha slow digestion process of a real meal. In my mind it is worth it. Am I eating 300 g of protein a day, certainly not. I be able to fit much more food into tha equation at my size, plus I like to maintain ketosis whenever possible. Is casein worth it in my eye, yes. I have been down that road and have seen effects first hand, especially when going up against whey by itself... Not to mention most recently there has been a study or two done that has shown Whey + Casein to be more effective than just Whey in terms of recovery. It'll try to locate it and post it if others are curious.
Regardless IMHO nothing will ever trump solid food.
