PS4 and Vita are terribly slow over wifi on RT-AC66U.

[Shaddap]

Here are the speeds shown by my PS4 with my current settings:

http://i.imgur.com/i8nDvkV.jpg

http://i.imgur.com/g7eR6sd.jpg

Ridiculously, I get better speeds when I set wireless mode to Legacy as seen here:

http://i.imgur.com/TzBRokQ.jpg

http://i.imgur.com/Emg1Fld.jpg

As I mentioned earlier, my AC66U is connected to an Actiontec MI242WR Rev. I via LAN-to-LAN, in the exact same manner my previous router had been connected to it. I reset the Actiontec to factory settings when my AC66U arrived and used the exact same setup as I used for my Netgear WNDR3800 running dd-wrt.

 

[ColinTaylor]

You said earlier that your Vita is now working fine. If that is still the case then everything suggests the problem is with the PS4 rather than the router. Try recreating the network settings on the PS4.

 

[Shaddap]

@ColinTaylor: Welp, turns out I'm an idiot. Sony released a beta firmware for the PS4 about 2 weeks ago, which I installed and encountered no real issues with when connected over wifi on my previous router. My AC66U arrived this past Friday and I couldn't understand why the speeds were so awful. I started to wonder if that had anything to do with it after I took the screenshots. I reverted back to the current stable firmware on my PS4 and lo and behold, great connection speeds have returned.

I apologize to everyone for my incompetence but I'm really grateful for the help and suggestions I received here. Thank you all again!

 

[ColinTaylor]

Great news Shaddap.

I didn't even know they did beta test programs for the PS4! I hope you'll be reporting the wireless problem to them.