So why are you moving 5gb between PCs? Especially on a small flash drive rather than a portable harddrive (which comes formatted with a more appropriate file system to handle large files).

Does it really matter why? There are innumerable occasions you might have 5GB+ of data you want to quickly swap between machines. DVD images (especially OS install ones) spring to mind, and it's not uncommon to want the image itself, not to unpack onto your drive.

Portable HDDs are bigger, more expensive, more fragile, and generally worse in every way (except transfer speeds) than USB flash drives for occasional short-haul data transfers. Writing 10G+ images onto a cheap 16G USB drive and throwing it across the office is a relatively common occurrence here.

lol. I use NFS for "throwing [data] across the office". Faster than disk transfer and no physical media involved.

That's ok but you should also consider the use case of unconnected systems.

Why not? A usb stick is cheap, small and durable.