Summary: Using the firmware out of the box works fine for me (Firmware: DD-WRT v24SP2-MULTI (09/27/12) std). I haven't tried flashing anything else. I use this as an AP, not to handle the WAN, but at one point I was using this with a modem and had no issues.
Before You Buy, Read the reviews for both comments and especially tips
Paper Boy, Amazon
27 August 2013
Summary: I tried my best to use the DD-WRT pre installed software; the settings just didn't work well. I then downloaded and installed the "1.86 EZ setup" software.which the "wizard" had a problem detecting my internet connection. I did fix it manually by going to the "WAN/LAN settings. Then it was EZ.
Summary: This router is great and did everything it says it does and more. The only thing keeping it from 5 stars is that it came with a heavy duty business environment installed on it that is not consumer user friendly.