Useless, DO NOT BUY!
It is completely unreliable, it loses the signal, and has a very odd behavior in general.
I also managed to connect 2 DAP-1620 units to run a wireless network for IPTV, it worked as long as you did a factory reset on both and configured them but as soon as one of the 1620 units lost power supply the link never went up again as it should. It also failed to stream IPTV stably, pixel errors became a bit now and then.
The latest firmware is slightly better but it is still very unreliable as only regular extender and other devices prefer my router as AP and not the DAP-1620 device even though it is closer.
As a WIFI-> Ethernet bridge, however, it works quite well. So that function works anyway.