Good review.
I agree with a lot with what was said, strong points and set backs.
In regards to the treble, the HD800 definitely falls in line with most other neutral headphones that at times will have "hotter" treble, so to speak. The reason I truly believe it is mainly the recording coming into play is because of the fact that it is only on 5 - 10% of my music, and the same thing is shown with the K1000 and W5000(on the same music), as well as all of the grados I've owned. But it's all perspective, as plenty of people have said that each of those are bright at some point. Regardless of it being either the headphone or the tracks, it is something to take into consideration if you are sensative to a brighter, more neutral sound, or prefer a smoother or darker sound. It is no coincidence that bassier headphones often have a smoother sound and vice versa. Neutral cans sacrifice the low end for detail/neutrality and the bassier cans sacrifice the extension of the highs for smoothness and bass response. But this is just all IMHO.
I'm also confused in regards to the treble, because it seems like with some people, it's all of their recordings, or even most. Mine is basically the same 20 songs that when I hear, I must skip immediately. lol It would be interesting if we could find out if this is simply due to hearing preferences, gear, or what.
In regards to the bass, I agree with everything you said and that is exactly how I feel about it. The bass is there, it is quality, but it needs just a pinch more quantity wise. There is more bass quantity than the K501/K701/W5000, but probably not as much as the HD650. Now, the quality is better than on any of those cans, but it would be nice to have our cake and eat it too. Reading early impressions, I dreaded this, and if it weren't for this aspect, I could live with the HD800 as my only can permanently. Unfortunately I will need a second, bassier can.
I won't comment on everything else, as the areas where the can does great is pretty easy to see.
Thanks again for the review.