Determination is an interesting stat to theorycraft; the variable being the healer and thier gear ilvl or gear choice in stats. The way I look at the stat: Increased Damage and incoming heals is an interesting mix of shortening the length of the fight while adding more to the effective health style tanking. I do not have the time to parse the logs; if you were to do this I would be interested in seeing what's the percentage increase in healing recieved.