Foyers tend to be more formal than not, being for show to guest as opposed to everyday use by family members. The ease of care, using both rooms as one, and the flow of traffic make this a very popular area for wood floors. Good cleaning habits are very important part of maintaining a wood floor, high traffic or not. Bathrooms - a working day to day bathroom would not fair well with wood floors, due to continued moisture exposure. On the other hand a guest bathroom would be fine.
Regular maintenance is required.
Rolling furniture, chairs, TV stands etc., can damage the finish very quickly, if used day to day. The finish and color will be affected by this. Darker colors tend to show traffic quicker, where as natural wood colors of oak and maple do not. High traffic areas need special attention when it come to recoating. Make sure the finish being applied is compatible with what is there and is of the shine that will work well in that area.