I have gone back and forth between the US and Mexico many times with an iMac, as well as the Caribbean and South America, and it is treated as a personal computer, like a laptop. I have never been questioned by any country or asked to pay import fees.
I use an iLugger for my 17" '06 iMac Core Duo. I have not had problems with it as carry-on luggage on trains, buses or planes. The small size has allowed it to fit in overhead storage for all of the above forms of transport without question. However, the current 20" may be another matter on airliners, definitely not the 24".
The iLugger is
not suitable as checked luggage. And the manufacturer plainly states that it is not and discourages use of it as checked luggage. I also would not trust an iMac in the original Apple shipping box in the luggage hold of an airplane. An airline baggage handler and a package express courier are two different breeds of being. There is no telling how many times an iMac could be drop kicked between your home and your destination on an airline!
I would trust an iMac to no less than a
hardshell case for checked baggage on an airline, a railway line or a busline.
Dah•veed
16 SEP 1810 The Cry for Freedom - ¡Viva México! ¡Viva Independencia! ¡Viva Libertad!