Pros : I started out using shelf paper...liked it, but WAY TOO expensive if you do any amount of firing!! Than ordered a 'lesser' kiln wash, and was EXTREMELY disappointed! After talking to one of Delphi's awesome customer support people, he hands down recommended Primo Primer for any/all firing needs. We tried it, and have been using it ever since! LOVE IT!! The price is awesome for how long a container lasts....follow the directions, although I like to mix my wash a little thicker (heavier on the Primo Primer powder) so as to assure a nice fire and guarantee no sticking. I always prime, than dry in the oven (if I am on a tight schedule), or just leave air dry for at least 1 day, so as to assure that the shelf is definitely dry. It's awesome, give it a try!!
Cons : Really none....
Other Thoughts : You get what you pay for.....meaning, if you try a lesser expensive kiln wash, you may not have much success when you fire! If you use Primo Primer, you will be consistently pleased with your final product!!