If it helps - when I bought our 2.7 CRD I looked at cheaper V8 vehicles that would cost more in fuel, and the better engineered (in my opinion) Mercedes diesel and gear box that cost more up front but less in fuel.
I have not driven the V8 but am very happy with the diesel cruising, 4WDing and 3500kg towing. I'm not confident in the comment being critical of the diesel's performance.
I have no trouble getting parts - Jeep, Mercedes or aftermarket mobs always have what I need in stock.
Can't fit a second battery into the engine bay of the CRD - I think you can in the V8.
Sure the CRD doesn't sound like a V8 - but I've always loved the sound and smell of a diesel.
Unless you wear gloves though - don't chew your nails after filling it up at the diesel pump...
. I get about 750km out of a tank which is great going bush.