The wireless NIC of the PS3 is crap. Plain and simple. Sony really dropped the ball on that one.
And as the OP runs a double wireless setup (server/client both WiFi to the router), I wish him luck in even streaming the most basic of formats.
I even notice lag/packet drop issues when running the PS3 wireless for online gaming (ever so slight, but it's there).
My timing is ALWAYS off when I game wirelessly. My timing rocks, and gaming is great when wired. And I don't think it's in my head, because I have tried several times, and it just doesn't feel right wireless. Maybe I am tripping but I prefer wired, specifically GB.
I have had no issues with NetFlix over my wireless N network as of yet. But I haven't actually used the PS3's wifi NIC for NetFlix yet. The only time it is wireless is "crossing the bridge" to my gear at the other end of the house from the router. NetFlix works fine "across the bridge" to the PS3 down there, which is wired to the DAP-1522
This end of house (DIR-655 N router) <------------- N bridge
------------> Other end of house (DAP-1522)
All devices involved with PMS, and gaming on either end of the house, are connected to their respective networking device (DIR-655 and DAP-1522) with Cat5e or Cat6 ethernet cables. The only wireless is "crossing the bridge" (and a couple "browsing" laptops), which stays steady at 130 Mbps, sometimes doubling....haven't figured that out yet, but steady 130 Mbps is plenty good for what I need.
Would I recommend going wired if possible, absolutely. Why limit yourself/network or have to sandbag your PC to squeeze the best qualities possible, in a wireless environment, to possibly the worst wifi NIC out there. The crappy little clip on wifi adapter of my 360 worked much better than the built in PS3's.