(Sorry for the late reply--don't get on here often)
Hmm; I would assume if the USB connections are the same, that they should work, but I hesitate to say so, because I'm pretty sure USB 3.0 draws a bit more power than USB 2.0.
USB 3.0/3.1 does transfer data faster--especially, the larger the file, the faster it goes. It comes in handy if you ever deal in large files or just need the speed at some point in time:http://www.diffen.com/difference/USB_2.0_vs_USB_3.0
Personally, I would go with a new case, since most new cases offer the following over the 630i case:
1) Better ventilation
2) Toolless installation of hard drives (at least more so than the 630i)
3) More options for cleaner/easier wiring/cabling
Newegg is a great place to look (if you're in the U.S.); I use them for their customer reviews alone--excellent resource.