Hi, yes there are pro's and con's with clay plaster the main one is plasterers not understanding how it should be applied the main comparison i get is its not as hard as Gypsum this is because Gypsum based plasters have a chemical set when water is added it reverts back to its original state and goes hard, its an interesting mineral when its being produced or cooked in a kiln it precipitates water this is why its a good fire preventative material and this product can be re-cycled over and over.
Clay has a mechanical set i.e. it needs compression with a plastic or japanese trowel to give its hardness but at any time it can be repaired as water will liven the surface so it can be re-worked but i can go through this in more detail later...