Remember, though, that hardwood floors are not meant to be perfect in the same way that tile, marble, Pergo, or another artificially created flooring would be viewed. Natural wood has imperfections and variations. When observed as a whole, these variations just reflect the character and uniqueness of a "natural" floor.
Some imperfections and color variations are expected with all types and ages of natural wood floors. Some of this is from grain pattern variations, natural knots, burls, and effects of sunlight and oxidations on the wood. Dings, scuffs, and surface scratches will always be present to some extent as wood, even with a coating of quality finish, is softer than most things that come into contact with the surface, like: furniture legs, dog nails, shoes, etc.
If a color change is required, "damaged" or "contaminated" areas are too extensive, then a full site-sand might be required. Otherwise, a buff and coat can help minimize or improve specific areas of injury, properly protect your floors against natural wear and tear, and restore the overall luster or shine that you had when the floor was new at half the cost of a full sand and without any of the dust or odor.
We expect your floors to look fantastic once completed!
Love your hardwood floors again!