I was in a music shop in Tokyo this morning, as I just bought a very expensive microphone from them, they were very helpful in letting me try out all their top end headphones, Stax 009/007, Beyer T1/T5P, Fostex TH 900, Senn H650 etc and with different music genres. After hearing all those nice things about the Stax 009/007 on these forums, I was a little disappointed; don't get me wrong, they are truly excellent headphones, but for the price of the headphone/amp combo, I think the LCD-3 is the top winner hands down.
The Stax are truly excellent for jazz classic and acoustic music, but with the LCD-3, you get the same/similar clarity but with that extra fullness in the bass department, the 2 Stax's just do not have nearly the bass extension or the richness of the LCD-2/3. With other genres like pop or R&B, the punchiness is there but not enough bass volume or extension like the LCD-2/3.
For pop, the Beyer T1 are the best among the ones I tried, but still lacking in the bass department comparing to the LCD-2/3, in fact none of the headphones I tested in the shop can produce the kind of bass quality comparable to the LCD-2/3 at all. The Fostex in my opinion is a joke, for the asking price, so lacking in quality and clarity, it doesn't sound that much better than the Senn H650 to me.
I think the Stax 009 do sound very similar to my Senn HD800 but less sibilant, they are top headphones for jazz and classic, but for me, the LCD-3 are my perfect phones, versatile, with top clarity and flat FR.