Short version: fantastic router, don't hesitate to buy.
The DIR-855 has a LOT of options, which could intimidate? I am familiar with manual router set up, which means that I am unable to comment on the enclosed CD and the device's auto-set up procedure. But I think that working with the manual should see anyone on the right track, with the majority of advanced options unneeded -- perhaps even best avoided -- by the uninformed.
The 5Ghz wireless has improved my WiFi *precisely* as advertised, so for that reason alone I am extremely satisfied.
Whether you absolutely *need* a display panel on the front-top is debatable, but I figured that the additional cost (compared to the DIR-825) was worth it? I hate the bright blue LEDs so in vogue on computer peripherals these days and find them annoying and highly distracting, especially in a front room while watching a movie in the dark. This router's (blue LED) screen automatically shuts down after a few minutes, leaving a single blue power light illuminated on the front.
Another reviewer commented on the heat generated by this unit. I can't say that I've noted excessive temperature compared to previous routers, but it does run ... warm.
In use: WiFi connects a Mac desktop and an iPad. Ethernet connects a Mac Mini, Xbox 360, a Wii, and Skype phone hub. ISP is Virgin cable.