JD2718 is one of my favorite bloggers and I agree with most things he writes, but not his post on AP calculus.
I taught AP for more than 15 years and found it to be the best course I ever taught. I never thought of it as a test prep course as it is impossible to prepare for this exam the way kids prepare for regents. No two questions are ever the same and memorization and rote repetition don't help. For the first time kids have to learn to not only read the question, but to carefully analyze what is given and what is being asked. Much like a detective solving a crime, they must use the evidence to arrive at a conclusion. A student once told me she felt much better about her calculus AP exam than any of the others she took because here she had a chance to apply her knowledge. If she forgot a particular fact, it wasn't harmful because she could use other clues to find what she needed.
As for the calculator, I happen to feel this gadget adds another dimension to the problems and allows students to find solutions to problems that are unsolvable by hand. The calculator alone does nothing. Each problem requires a tremendous amount of knowledge and thought before the calculator can even be touched.
I never did real test prep when I taught AP. I gave my students AP caliber questions and let them work them out. At first the success rate was minimal but it got better as time went on. The kids told me they were able to apply the skills they learned doing these problems to other aspects of academia and real life.
Getting a 4 or a 5 on an AP exam is like licking the icing out of the bowl after your mom has made a cake. The cake is great on its own without this little extra treat. The real benefit is in the knowledge obtained and the confidence these kids gain while taking the class.
I'm sorry JD didn't enjoy his experience. I bet his students did. I hope he changes his mind and teaches the course again. No one gets really good at teaching AP until the third time around. Even then, its a learning experience for everyone involved. Teaching AP is something I really miss.