regarding my post: I'm using/was using the word 'core' to refer to OEM core. I would consider a knock-off core.. not the core. I.E. Drive Shaft Shop wouldn't take aftermarket axles as the core.
Don't they all use factory cores? I thought they all used factory cores. I haven't looked into this for a while, but they should absolutely identical. The differences would be in quality of CF, assembly, leather, etc. etc.