Got my WA7 in last night and WOW is this thing amazing. The build quality would leave Steve Jobs speechless, yes it's that good! The shipping weight is 14lbs, that alone should tell part of the story. No corners were cut, or as John Hammond might say: Spared no expense. It will be hard to upgrade someday, if I so choose, because I've seen few other designs that look this good.
Luckily I don't think I'll need or want to upgrade for a long while. I haven't had much time to listen, I've been sick this week, but what little I have heard has been excellent. It has really made my HD800s sound fun while still retaining that huge soundstage and hyper-detailism that makes the HD800s...well, HD800s. But now I don't have piercing siblance, or those moments of aural flinching when some poorly recorded treble spike comes slashing into my ear drums. The coldness of the HD800 is warmed just enough to make them extremely fun, but not so much to cause harm to the sound they were made for.
If I had to make a complaint, about the only thing I would suggest is that the glass block have some sort of metal lip it fell into so that it was secured from sliding around the top. I mean, that block of glass isn't going anywhere, but it will shift around a little when you are wiping your fingerprints off of it, and your OCD will kick in trying to center it back on the amp. I suppose too, that some will be put off by the fake LED tube glow and the USB powered DAC, but neither of these things bothered me. The sound quality will speak for itself.