I have had the good fortune to experience IDCs at tropical paradise resorts, at Calypso in Tampa, and to work in several roles and situations as a dive instructor. Any IDC will teach you the PADI system, standards, etc. Any of them will teach you to pass the IE. But that OWSI certificate is only a starting point. At Calypso, I learned how to juggle scheduling, deal with difficulties, link courses (make money!). Their pool and classrooms, combined with realistic local diving, made it convenient.
The store and staff are examples to be emulated. Course Director Larry is organized, diligent, pleasant, and highly intelligent. Course Director Gary is just as smart, as well as highly experienced and a fountain of ideas and techniques to deal with teaching and making a career as an instructor. Together they are an awesome team. And they are supported by a group of Master Instructors, and Staff Instructors.
Tampa is inexpensive. Expensive flights or outrageous hotel rooms are not needed.
PADI Master Instructor