Phew..................... What a question!
Not sure you may get many detailed responses as the answer is very long and very dependent on your personal attitudes, experience and ultimate aims.
Perhaps you should outline what you are looking to achieve and ask in that context which would be a better option for you. To be honest a Public cat CofA, a Private cat CofA and a Permit all have their advantages and downsides depending on what you yourself are looking to achieve.