When I copy a “normal” set of files using Samba (which is what Windows uses when dragging and dropping files in Explorer), I get between 10 and 15 megabytes per second. That’s around 100 to 150 megabits per second. It’s not gigabit speeds, but it’s faster than 100 mbps, so the interface is needed.
If I copy a bunch of really small files (1-2 kilobytes per file), then my speed drops significantly, but that’s somewhat expected with Samba, especially with a LInux host (which is what the drive is running). If I copy the same small files from one computer to another, I get sub-10 megabits per second speeds as well. Granted, they’re better than the My Book World, but a computer also costs a lot more and has a much faster processor.
Have you tried transferring through FTP? It might help because FTP has less CPU overhead than Samba. With large files, I usually get speeds of 30 to 40 megabytes per second through FTP. With smaller files, it’s slow, but it’s still a lot faster than Samba. Plus, the FTP client can keep track of what’s already been transferred, so if you have to reboot, you can pick up where you left off. If you’re using Windows to copy the files and something goes wrong, it’s not exactly easy to figure out what’s left.
If you do use FTP, you should set your FTP client to only do one transfer at a time. If it does multiple transfers, the overall speed will drop.