Actually, I have sent back two sets of N wireless gear in the last month or so. In my experience so far, the D-Link hardware is the least worst.

So that I can understand you clearly, are you saying you can or cannot stream HD wirelessly? When I read your words, it seems you can wirelessly stream SD, but not HD. Wired has never been a problem for me. If I temporarily run a CAT6 line down the stairs, I can stream 1080i cleanly. It's wireless that gives me trouble.
So, can you stream HD (720P or 1080i) with ease via a wireless link?
Bye.
