Sprint version comes with 2gig of built in Rom for apps and 16 gig sd card for storage. So you save money over Nook by not having to buy sd card.
Nice thing about the Tab and other 7" devices is that it's portable and about the right size for car computer. With its built-in bluetooth and GPS, you can car mount it and use it as car computer. You would need data but I can just pop in my T-Mobile sim card on mine and get voice and data.
I bet most of these are not refurbs but brand new units. Retailers have to be sitting and choking on these things and desperate to unload. My AT&T unit was definitely brand new unit and even better quality than Apple refurbs I bought in the past.