Proven naturally aspirated engine will be more reliable than a new forced induction engine all day. More efficient, yes, but more stress and more heat is a definite downgrade.
Discussion
Without a doubt.
My curiosity is how much life will it realistically take off the engine vs savings on fuel.
If I were buying a vehicle with +150K miles I'd be leaning towards the V6. In all likelihood I won't drive it that long.
Resale might take a hit, but living on a bitcoin standard I see any vehicle as sunk cost anyway.