Everyone has a love/hate with treble - if it is there, they can't decide if they love it or hate it. But as with bass, we all know how we feel when it ISN"T there.
I am with you - I'd MUCH rather have an HE-400 living on the bright side than go to an LCD and feel like my music was on life-support. Most of the music that really gets me pumped NEEDS treble. But not everything I listen to NEEDs to be 'smooth' and 'natural'.
You have listened to the LCD 2/3 and felt they are lifeless?
The problem with the HE400 treble is not that it has too much or too little, its that it is a harsh tizzy treble.
My B&W speakers have more treble than the HE400, but its silky smooth treble that makes my ears tingle and puts a smile on my face. Now if I could just make them into headphones.
Every time I listen to them, after, I feel that the HE400 just doesn't sound right. Its a brave person that listens to the HE400 with no EQ. Over time, its just not bearable.