Not a surprise
It has always been quicker to shunt the data in bluk around that it has been to transfer it directly over the 'net.
I used to have to recalculate OLAP databases for a client. Their server was fine for serving the data, but it would take 6 hours to recalculate the 90MB (compressed) cube. It was quicker for me to copy it to a Zip disk, drive home, copy it to my PC, recalculate the data and copy the resulting cube back onto the Zip and drive back to the office (an hour each way).
Hard drive capacity and the speed of cars/trucks has always been more than a match for internet connections. If you ship a NAS full of 6TB drives, you'd need one heck of an internet connection to complete the transfer before the postie turns up with the array... Whether it turns up in one piece is another matter. ;-)