Great post macbob! I would have definitely returned mine as well if I heard tizzy or confused treble or god forbid ringing. I have no problems returning products I find to be problematic. In fact if I wasn't so in love with the K812 I would have just asked for a refund instead of a replacement from RazorDog. He actually had the HD800 for cheaper (in stock) than what I got the K812 for, and I thought long and hard about it before going K812, and thought about it some more when sending it in and asking for a replacement.
As for my replacement pair. It's stuck in my local post office. Expected delivery has been updated to Monday. If I get a pair that is strident/tizzy/confused I'll let everyone know and return my pair.
Yeah, most headphones are mising information at 2K~3K, it's quite unusual for headphones to be linear there instead of dipping hard off a cliff. I actually like it a lot. The K812 and Spirit Pro both exhibit this trait which I personally like and think of closer to "neutral". The Signature Pro dips pretty hard there, like all other headphones I've tried in my profile. It's the more common tuning and is not unpleasant or anything, it's the lesser fault of ommission rather than inclusion, so little harm done, but I'm just missing information there that I like hearing.
Good luck on your delivery, M-13! Look forward to hearing about your replacement pair.