I'm looking for a comparative analysis of Ford's diesel engines. What are the good and bad points of each engine? Fuel consumption, reliability, durability, power, ease of maintenance, cheap replacement parts, known problems, etc.

mid '80s 6.9
early '90s 7.3IDI
mid '90s 7.3PS
early '00s 7.3PS
'05 and later 6.0PS