Hi,

I have no experience w/ these, but I do know many manufacturers have had
head gasket problems in the last 20 yrs or so, and the solution to many
of them HAS been a metallic gasket of some type.

An example would be the Toyota 22-R engine used in many of their small
pickups during the '80s and early '90s: they were notorious for blowing
factory headgaskets. My '86 ate its h/g at 69k miles (which seemed to be
about "average" mileage for failure at the time.) The "racer" types were
using copper aftermarket gaskets w/ good success, and, in '88, Toyota
switched to a factory metallic gasket. My '88 has it, and it seems to
have worked!

I'm not sure what the difference between the two types you described
might be other than that the "expanded graphite" is a fibrous gasket
like many OEMs, the "expanded metal w/ graphite" might be a sandwich
affair: two metal sheets w/ the fibrous material between them.

Maybe something like the latter would help the Subies that like to eat
h/g's.

Rick