GMP guidance provides ample guides in ensuring the safety and quality of drugs manufactured. As the name implies, it serves only as a guide, not as a rule that you MUST follow.
This leaves us a lot of freedom to implement methods most suitable to our own needs, and methods better than what is practised by others. More often, you will always need to support your unique ways of doing things to satisfy the auditors - leaving most of us going for the safe approach and instead 'follow what others are doing.' Thus, lacking in creativity.
Another 'problem' of the GMP guidance is its non-specificity. For example, does a buffer room require an interlocking system? Why can't you release your products direct into a Quarantine room; from here it is released directly to the approve store? Must you need a buffer room for finished goods before going into a quarantine room? Is it compulsory to have a quarantine dedicated area, or can we use flexible methods to identify quarantine items, such as by ropes and quarantine labels.?
There are many more issues pertaining to GMP guidance. I hope I can have some comments or share of experience from you all out there....