Chosen Solution

Does anyone know if the SSD in the late 2013 MBP 15" Retina or 2015 MBP 13" Retina works in the 2017 27 iMac?

SSD in the late 2013 MBP 15" Retina or 2015 MBP 13" Retina works in the 2017 27” iMac. Yes, they will work. But! The speed will be slower, cause 2013 MBP uses PCIe 2.0 SSD’s, not PCIe 3.0 SSD’s

Here’s a good reference: The Ultimate Guide to Apple’s Proprietary SSDs