We see Dr. Conlon and are very happy. I left his office with more clarity than any other appointment I've been to. Super nice guy, great with my child, and great with us worried parents, too.
I've never seen Dr. Shapiro, so I have no basis for comparison. I'm sure he's great as well.
I'd keep your appointment with Dr. Conlon and then if you can get in with Dr. Shapiro and you'd prefer to see him, just cancel it the appointment with Dr. Conlon. I think either way, you're in good hands.