I am not sure about what Tyll meant with tizzy, as I thought about something else than treble only, for example this definition from here:
-state in which you feel very worried, upset, and confused
-a highly excited and distracted state of mind
Maybe, at the end and in the sense of disappointment, while expected more, he simply got displeased, maybe even confused, by their presentation/performance? I mean, I can imagine that someone could get annoyed / bothered by lower level of performance, while you expecting flagship to perform close to perfect, so, you call them tizzy, instead of call them bad or else, which also caused a lot of comments, because while he did said that he do not want to trash them, he did it anyway.
Same happened to me, when I got pretty confused with PS1000, so, I dont know, just saying.
Thank you for this information!
I want only clear what tizzy is. But for me the K812 is not a tizzy headphone - the K812 reproduce what it get from the source.
Now I hear "Eneida Marta, Lope Kai" - I am very impressed from the K812, after about 80 hours hearing trough alls my classic, jazz, pop/rock, ethno/world-music, japan-drums, celtics, .... I could say the K812 is an additional flagship in the top region of headphones.
The K812 sounds very clear, with air between instruments or voices; very good deep, dry, powerful bass; balanced, clear mids; clear highs.
Yin and Yang .... AKG K812 - Denon AH D7000