Doesn't that defeat the purpose of the sp3, which is mobility? It's one thing to put a microsd card in there for storage. It's a whole other thing to lug around a ssd usb with it.
Heavy lugging. My 240gig ssd is very slightly bigger than a thumb drive. I keep it in my bag with several cheap thumb drives. I have a handful of $5 thumb drives I keep with me to give to data to friends when the occasion arises.
Example of one that I have:
http://www.amazon.com/VisionTek-240...e=UTF8&qid=1420065711&sr=8-3&keywords=ssd+usb