I have just ordered the HE-400 and can't wait to get my hands on it after reading your post and updates. FYI, I have also ordered the Bifrost and the Asgard (Jason's recommendation). My music source is the iPod Touch (latest gen). In your trials, did you experiment with different sources , e.g. laptop, a music player like Cowon.
Curious to know if the source makes a huge difference.
Bifrost>Asgard>HE400 is a pretty solid setup, just know that it will be very very detailed and revealing, so be prepared that some low bitrate or poorly mastered music will sound like crap, while better mastered lossless stuff will sound really great.