Re the original posters question, Thunderbolt and replacing the blade SSD in the Mac aside, I’m not sure I saw anything definitive about how to best use the fusion drive if the decision is to replace the HHD with an SSD. Can it still be a fusion drive? Will the mac know to keep the system stuff for booting on the PCI based SSD?
What would happen if I didn’t “break” the fusion before pulling the HHD and simply installed the SSD in the SATA spot. Would it automatically try to create a new Fusion setup? (obviously a backup of the original system would be on hand).