Having both bands available at once in the 2012 AirPort Express (a
feature added in 2009 to the Extreme and Time Capsule models)
allows your network to perform at the highest possible speeds no
matter how distant a device is from the base station while it
remains in range of a signal. That’s a significant improvement,
and makes the Express a much better value, especially compared
with equipment from competing manufacturers, such as Linksys.