Fortunately in my area we have the choice of drywall or plaster being the same price for labor. The last 3 houses I did I used knock down spray but went back to the sand finish plaster with smooth baths and kitchen. I like the plaster because I can skip prime coats and paint with flat latexes, smooth may get primed. 18 to 20 a sheet labor for a 4x 12 board hang and finish