Ok right beside me i have New i mac i7 2.9 12 gb ram and Mac pro 2.66GHz Quad-Core Intel Xeon with 8 gb ram. I have cinema 4d installed in both of them. Now i have scene that i have rendered same one in both of them and mac pro is 15 min faster then imac when it come to rendering same scene. In my opinion i think imac sucks big time with all the dame issues and bull **** that i head to put up for 8 months. I am keeping mac pro buying two 24 inch lcd and that shiny half pissed filled imac screen can go **** it self.