If you have an offset smoker, and like it, I don't know that I would replace it with a ceramic smoker at all. It can and will do what any ceramic will do, but you will have to crutch the meat, inject, mop, or more, to get the moisture you can get with ceramics. But hey, it is just another way. The beauty to the egg, is being able to perform many different tasks, not just low and slow. But the characteristics of a low and slow on the egg are high moisture content due to the ceramics. Why is pizza in a clay brick oven better than in a grid or gas fired oven? Why does modern construction add a moisture barrier both inside and out on an insulated wall of a house? Some places you want moisture, some you don't. There is no insulation on a steel smoker. And you can only add so much moisture and get it to retain it. I am not arguing right and wrong, or even stating that an egg is better...but you asked why it helps to retain moisture better, and I am passing along my understanding of it...and not from a hype standpoint, but rather from the physics behind it. Could physics be used to hype something? Yep, probably been done before and will be done again. But I don't have to work too hard to produce very moist results on my egg...but then I am just a rookie.