I've purchased quite a few "as is" items in multiple categories over the years, and in general, I've encountered very few issues. As others have noted, there are many times when I've received what is clearly a brand new item, so I would guess they were just overstocked items or items returned by customers that for some reason simply didn't qualify as still being in new enough condition to send out as a regular order.
However, I've stopped buying "as is" clothing because my scent sensitivities can't take the odors that people leave on clothes when they try them on (or even wear them for awhile before returning them). And it is often impossible to know whether washing an item would get rid of the smell. But all that said, I've also ordered new clothing items and still ended up receiving stinky returns instead, so I can't totally blame the "as is" designation for the way QVC handles clothing inventory.
Last year, I purchased five different sets of Valerie's ribbed mercury glass hurricanes "as is" because they were half the price of the new ones and lots of color options were available. Every set was perfect. You could tell that the light units in some had been tested, but others seemed brand new. Such a bargain! (And they're still available; I'm constantly convincing myself that I don't need to stock up on more for gifts.)
But one of the strangest "as is" items I've received was a different Valerie hurricane, the lovely celebration/fireworks version. The battery door on the light unit was slightly dented and broken, as if someone couldn't get it open, and the light strand was torn into pieces in all directions—there were about seven or eight little pieces of light strand scattered throughout the packaging. I am guessing that a customer simply couldn't figure out how to uncoil the strand, but it was a mess and definitely unusable. Clearly, nobody really inspected this item before putting it back into circulation!
And I guess I should also mention that out of the three times I've received the wrong item from QVC, two of them were incorrectly packaged "as is" items. (The third was a pair of pants that was sent to my address rather than the actual buyer's by mistake.) Overall, though, I continue to enjoy the great deals that are often available in the "as is" category and don't worry about potential issues—QVC is great with returns.