Looks like we both had the same question in mind at the same time!! My thread is right next to yours. Think we both got the same answer, all in all not a bad engine at all, in fact sounds pretty darn good.....
Lots of myths out there, best get info from the first source, those of us who have had these engines.
I have had 3 Vulcans, 3 Essex, now have 2 DOHC
Vulcans are "old school" solid, old proven design, but iron on iron so heavy and rusts. They need regular coolant maint or they have real problems.
Essex blow head gaskets, just a matter of when, not if. Aluminum head on iron engine is not a good idea. Real torque engine, does not rev up well. Ended on Taurus/Sable in 1995.
Duratec is modern all aluminum, light weight, proven to be a good design. Now 15 years in the mill and any weakness has been recorded here. Good torque, good rev, quiet. PCV
is in a real PAIN of a place, and needs to be maintained. Vacuum hoses and PCV
hoses seem to rot early.