Tom, I used the cookies because they were easier to use than grinding graham crackers and making the crust from quasi-scratch.
And Jane, this is the first time I used the pecan Sandies. Last week, I used Keebler Sandies Shortbread cookies that didn't have pecans. I wanted to try these, but I when ate one of the pecan cookie cheesecakes, I realized that I like the non-pecan shortbread better...of course, a graham cracker crust IS best, but I was going for convenience. I think if/when I make them again, I will make them with graham cracker crusts.