I debated on trying it with 2009, but like I said, the resource hunger put me off.
Also I'll let the users get used to 2009 before I setup a workspace that throws out everything they recognized about AutoCAD. People need time to adjust. Not a good idea when they are buried in a year long complex project.
I will say , I like the fact the Layer Manager is now a palette in both AutoCAD and MEP.