Well, it's generally less crowded this time of year, you can count on it for reasonably good weather, there's nice views of the river from the upper rocks, sandstone is a different medium than what they've mostly been on already (basalt/andesite only), and ropeguns that get annoyed by newbie groups stay far far away from PP.
After they've been out a few times, and show an interest in the sport and get geared up, I take small groups (2-3) to better climbing areas later in the season. I like to cap the club's instructional season off in the fall with a longer camping/climbing adventure like Harrison Peak near Sandpoint, ID or something like that.