The trouble with flash drives is they tend to be rather slow when you're writing to them, although they're quick enough when reading from them. Another problem is there are two operations needed each time. A network is simpler and quicker.

If you download SyncToy from Microsoft (it's a freebie, and excellent! Honest!), you can set it up to automatically synchronise your files at the click of a mouse.

SyncToy will work with almost any kind of drive... network, flash, internal or external hard drive. It's not intended for use with optical drives. It really is that good!