I recently bought and installed a TL-WPA 7510 Kit for my home. The installation and pairing was fairly straightforward, and my network's performance has greatly improved. My smartphone immediately recognized the new dual bands; I entered the password provided on the wifi unit's label, and both bands worked perfectly.
The wifi signal was weak on the second floor (old, solid construction with metal lathing inside plaster walls), so I bought another kit. When the new wifi unit went live, I again found it on my smartphone, entered the password from the label, and everything appeared fine. I then noticed that the ID from the first wifi unit had disappeared, as had both bands. Only the ID for the second wifi unit remained.
Did the installation of the second unit "erase" the identity of the first one? Is this something about which I need to be concerned? Other than this mysterious disappearance, both wifi units appear to be working well, and the network is operating faster than ever.