This is what I've been running and so far it's fixed the problems I was having with the router:
Setup -> Internet -> Manual Internet Connection SetupPrimary/Secondary DNS Server: Manually enter your DNS settings (this is optional but I manually change my DNS server because I like to use OpenDNS
http://www.opendns.com/Setup -> Wireless SettingsSecurity Mode: WPA-Personal
WPA Mode: WPA2 Only
Cipher Type: AES
802.11 Mode: Use only the modes that are needed for your devices. For example, I only have G and N devices on the 2.4Ghz, N and AC devices on the 5Ghz. So my settings are Mixed N + G for 2.4Ghz and Mixed N + AC for 5Ghz.
Wi-Fi Protected Setup: Disabled. Sometimes the router would fail to reboot and I was forced to power cycle. Disabling this seemed to have fixed it.
Setup -> Network SettingsLocal Domain Name: dgl5500.local (you can enter anything - I use Avengers.local). DNS lookups weren't functioning as expected on a Windows PC until I set this settings.
Enable DNS Relay: Disabled. Disabling the DNS relay made a huge difference for me and fixed various devices from suddenly not being able to access the internet.
Setup -> StreamboostEnable StreamBoost Bandwidth Control: Enabled
Enable Auto Bandwidth Estimation: Enabled - StreamBoost accurately estimates bandwidth in all my test with a Cable modem. If it's incorrect then disable ABE and enter high numbers like 100/50, test your speeds at
http://www.speedtest.net/, then manually enter the speedtest numbers. DO NOT LEAVE IT AT 100/50.
Automatically update StreamBoost: ***Update*** Try leaving SB Updates enabled first and disable only if the my network/statstics pages stop working for you.
All other settings are default I believe. I have some DHCP reservations but that's about it.