In my experience, consumer electronic "refurbs" tend to be new, but bulk-packaged and branded as refurbs. It's one way to clear out inventory w/o hurting the official price. When considering the labor cost of a trained electronics tech and the time it takes to diagnose/repair, it's not cost-effective to refurbish most CE products.
I've opened a number of "refurb" toys, and one can always tell if they've been opened before, because most parts are plastic and will leave traces of being pried open. All of those opened have pristine innards.
Returns are usually sold in bulk to various 2nd-hand outlets for pennies on the dollar, who will then take the time to go through the pile, sifting the good from the bad. These "recovered" items aren't sold in regular retailers, but deep discount outlets or on eBay, and are actual refurbs.
This probably isn't as universal for higher-priced CEs like tablets. Still, I'd really doubt that any of these "refurb" tabs are anything but clearanced items. We know retailers are stocking up for the holiday shopping, and old toys need to be moved.
As tempting as prices may get, my suggestion is to hold off for new product launches. Then, you'll have the option of either buying new toys, or old toys for really cheap. Black Friday (for US peeps) will have lots of bargains. I expect many of the Teg2 tabs will hit the $200-250 mark. First half of November is usually when new toys get unveiled. Asus TF Prime = Nov 9, Nook Color 2 = Nov 7. Kindle Fire will show up by then. Xoom 2 probably in same time frame, along with Tosh Excite.
In short, wait a couple of weeks.