"for hd video, wifi is NO SUBSTITUTE for wired enet.
try an mkv file; oftentimes it takes 2 or even 3 minutes before vlc (on win7 ultimate) begins to play, and that is with the very latest media bridge of ac to ac wireless (2 asus routers). this is as good as wireless gets for consumers and yet I have a several minute wait time."
That's your problem - the second you went into bridge mode you effectively HALVED your available bandwidth between routers.
It's like nobody learned the lesson that DD-WRT taught people years and years ago - wireless bridges SUCK and are no replacement for a proper signal repeater.
I have zero problems streaming 1080p video over my wireless network - why? Because I'm smart enough to not halve my bandwidth with an asinine network configuration, and I'm using one of the crappiest Belkin N-speed routers (with absolutely non-working port forwarding/DMZ on top of that!) I click a video from my media server, it's streaming pretty much immediately.