When we first used to visit WDW, we used priority seatings quite a bit. What I found was that too much of our time was dictated by where we were going to eat....always making sure we were at a certain restaurant at a certain time....it became more of a chore than a pleasant experience. Now, we very rarely ever make a PS. Our feeling is that there are so many good places to eat, that if we go to a restaurant and can't get in, then it wasn't meant to be and we head somewhere else.
The only exception to this these days is if we really want to go to one of our favorites but even then, if it is not a busy time of the year, we'll forego a PS then too. My advice would be to make one or two PS's for any restaurant that is a must for you, but do not make PS's for every meal; it will just make you go crazy trying to make each restuarant on time. Plus, how do you know you are going to be hungry when it is time for your PS each day....it's just not how we like to schedule our trip.