What are the pros and cons to setting up projects using the sub-customer conversion? (I am not looking to figure HOW to do this. That is the one thing I CAN find.)

Do you have expirience why it is better to use an estimate to creat a project or just starting with a raw project creation? This is the 3rd time I am setting this up in QBO Advanced from Desktop. I want to take everything that is under our current sub-customers and tie them to a project, which is not set up right now.

Thank you in advance for any responses to my question!