A:Answer I think a much more complete answer is:
This unit is an access point, you can connect to your internal/home network wirelessly.
Can it replace an Apple Airport? Well sort of... you CAN connect wirelessly to it, but it does not do all the fancy mobility stuff the Airports do for computers, they have a function that basically helps your computer "roam" in your house if you have multiple access points.
When this scheme works, it does indeed help wireless speed and access, but usually only on Apple devices.
So bottom line, it can replace an Apple Airport, but not at the same functionality level, which may or may not affect you based on if you are using the advanced Apple features already with 2 or more Airports.
Greg