I've been using styrofoam nucs for a couple of years now and have successfully overwintered colonies in them when they were new.  Just used 'as is' and never aired them out.  My biggest problem was/is feeding (more that I have to figure out a program during the winter than related to the boxes themselves).  I have noticed that the older boxes have yellowed on the outside after  two full years (summer and winter) outdoors, but otherwise are still in great shape.

As for frames, I use plastic (Pierco wax coated) both in my main hives and in the styrofoam nucs, and have never seen any problems with acceptance.  This is just a guess, but I think that bees pretty quickly 'smell up' a new box with their unique cocktail of aromas, regardless of the material of construction.  For example, checking a new nuc a day after adding bees to it, it looks and smells like bees (bee prints on the walls, smell of bees, etc.)

Bill
Claremont, NH - where, after posting the first net gain in hive weight on Sunday, corresponding with apple bloom beginning, the temperature has plummeted, and it is now snowing out.
' 

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