Don't let the fact that the exchange units might be refurbs put you off. The unit you sent back to them wasn't brand new either, since you had been using it. The refurbs are in as good or better shape than the new units, because the have been restored and have been through a second, even more thorough QA cycle. In any case, if you exchange it at Apple, you have no way to know if it is brand new or refurbed. They do exchanges from separately received exchange stock. Some of this exchange stock is new, some is refurb, there is no way to tell at the store level. They come in brown boxes. All you will know is that it is an exchange unit, but not whether it was new or refurbed.
