I know all the cool kids want REVIT to do all the work for them like flow or pressure drop calculations, but I am not one of them. They won't turn off automatically until you reach a certain number of systems or elements. I don't want to manually turn them off one by one. I really don't care about them other than they're most likely slowing down REVIT when I am working in large files. Either have users turn them on manually (so those calcs are OFF by default) or have 1 giant button that turns them all off and keeps them off unless turned on manually.
I second that. In my office we dont care about the calculations and systems. All we do is acurate size and make sure it fits. When we get the model from the eng to do coordination we have to go through each system and turn them off. Global off button would be great!