We have two in our household and they are highly regarded. It seems that those that own them love them and those that look at the specs but do not own one have less than complimentary things about them.
It's KitKat and no futher OS updates are supported
The refurbs we received were as new with no way of telling them from a new one but others have said they have had used items.
If you look at the specs you may listen to the "low res" "old OS" blah blah. I can say that they are superb in both ergonomics and battery life.