Never, ever, ever, use a USB stick for a portable hard drive's job.
If it doesn't need a cable then don't plan on moving anything fast.
Nomenclature!
USB stick is, any kind of flash on a stick. I've never used one that didn't either suck or suck after kinda limited use, even the really really nice "SSD on a stick" options. You're much better off getting a "SSD on a stick but it requires a small cable to hook it up" instead. Especially the ones where you bring your own drive.
I've also absolutely adored the little USB2.0 / FW external 2.5 enclosure I picked up for doing osx bullshit. It's got a "classic" SSD put in but it'd be doing just as fine if it had a 2.5" hard drive in there.