In my experience, which is now going on 40 years of reloading shotshells my choice of components was driven by what I had or could get in the way of empty hulls.
Paul we do need to be careful with primer substitution. As you can see in the attached link a simple change from Rem 209P to Win 209 in one particular load resulted in a 2400 psi increase (7040 vs 9400 psi).
http://www.armbrust.acf2.org/primersubs.htm