You will get a out of the box mill from a re seller.
Most the time all is OK but you may need to work on the fit of the Gib strips, sand out some high spots on the ways and adjust and grease the preload on the spindle bearings if they are too tight.
Most tables are +- .003" and spindle runout is under .002" which is fine.
They come with a spec sheet which I bet have nothing to do with the mill you receive.