Just thought I'd contribute that I've got a DIR-855 (running 5GHz only), firmware version 1.23WW, connected to a DAP-1522, firmware version 1.21 in Bridge mode.
Connecting the two was a frustrating time hole, but I got there in the end by setting a static IP on the DAP-1522 to match my DIR-855 network range and then using WPS. (The SSID has to be visible on the DIR-855.)
So far I'm getting a good connection, between 216 Mbps and 270 Mbps, but the units are only about 10 feet apart over two floors.
As others have reported, I cannot access all of the web features of the DAP-1522 with anything other than Internet Explorer. Irritating since I use Mac OSX.