Ahhh....3D! Haven't worked with that since '98 - Pro-E to be exact. I enjoyed 3D immensely, but haven't been able to get back to it since leaving that job for greener pastures I currently use Autocad 2004. The 3D packages out today sure would have come in handy at my previous job - HVAC for industrial applications(air turnover,make-up,de-stratophication units)!
Those sheet metal enclosures, some as large as UPS trucks, can be a bear to get the flat pattern laid out correctly using 2D