I second that. The 009 is the most comfortable STAX ever, and at least on the top 3 most comfortable headphones I've worn period. The 007 is really comfortable too but it's hard to get a great fit as there is not much flexibility in terms of earcup adjustment. And I prefer the fixed arc of the 009 as opposed to the self-adjusting headband of the 007. Sound wise I don't think it's as simple as the 009 being all together superior, but construction wise the 009 is much...
The bass of the SR-009 is faster, better extended, more impactful and more textured than with the HD 800. Compared to a planar like the LCD-2/3 or HE500, the SR-009 may not give you the same sense of weight/heft, but it will go as deep and it will kick as hard, with even better precision.
The finest Lambda ever made IMO is the Lambda Signature. The Pro is a bit too bright and edgy sounding to my memory.
None of the Lambdas can match the 007 or 009 in overall performance. The 00X are the leading duo in the headphone world IMO when it comes to refinement and transparency.
Been using the 009 for quite a while now with a modified SRM-006TS (superior driver- and output capacitors resulting in far more capable driving authority and improved refinement) and gotta say, while it sounds really great and I've spent many nights enjoying the heck out of the sound, I still find the O2 mk1s to be more up my ally. The 009 is as clear and resolving as I've ever heard a headphone to be but it doesn't put you "there" in the same magical way an O2 can do...
I don't think it's fair to compare a full-size headphone to an IEM. IEMs will never have the transparency and realism of a really great full-size headphone. Especially if it's an electrostat like the 009.The STAX certainly has less bass though (but no less extended and with superior speed and texture).
Just got me a pair! Only used them for a couple of hours but first impressions are definitely positive. Fantastic midrange, very pure and informative treble without crossing into bright/brittle territory and the bass has a bit of extra oomph to it without any intrusion on mids. Just the way I like it for portable use. And they sound reasonably spacious too for an inear, there is a decent amount of soundstage to them.
I definitely prefer these to the HD800.