In fairness, there's no reason not to take an obscene amount of time when cooking stock. Leave it on the counter slow cooking for 24 hours. You're just going to put it in the freezer with the dozen other jars of stock you already have.
What I like about the pressure cooker is that I make stock as and when I need it. Do I need stock for dinner tonight? Just put on as much as I need of exactly the stock I want an hour or two before, and done.
