Best practice is to use a manual /127 address for point to point addressing described here RFC2373
for EUI-64 ERFC 2373 dictates the conversion process, which has two steps. The first is to convert the 48-bit MAC address to a 64-bit value. To do this, we break the MAC address into its two 24-bit halves: the Organizationally Unique Identifier (OUI) and the NIC specific part. The 16-bit hex value 0xFFFE is then inserted between these two halves to form a 64-bit address.
I understand perfectly where you would use the /127 manual address assignment , but I cant really see the benefits in using the EUI-64. unless i am totally missing the actual purpose of this address function.
can someone kindly shed some light on the EUI-64 use cases specifically in a ISP WAN topology if possible. or point me in the direction of some reading material please.