Sorry but unless it's 50% off I don't bother. Too much to go wrong here. Let me share the scary story.
There are unscrupulous folk that need a motherboard because their laptop had blown parts. They'll buy the same laptop, make the swap and return it. It could even be a rare memory socket failure so they return the unit and the next buyer gets to find the issue and deal with it.
I am not a fan of open box items unless it has a steep discount. And that includes any claim the store was the one that opened it.
I'm giving myself one hour to reach a final decision. Right now I have it narrowed down to
Open Box Yoga 13 for $800
Open Box Zenbook UXUX31A-R5102F from a nearby Best Buy for $750. It was returned w/ one screw missing
Finally: the sexy new Zenbook Touch UX31A-BHI5T11
I'm a student that does mostly Office and Internet, and these all have the same specs, so should all be equally functional there. I have to decide if it's time to join W8 (or stick with a more familiar W7). From what I've read a lot of problems the earlier Zenbooks had have been corrected in the latest model, but is it worth $400 more than the open box one?