I am fine with the Utopia soundstage and dynamic. If u used copper wires, the Utopia has a lot more slams and bass with a more closed in soundstage, just use silver-goldmcables and u will love it. IMO, the weakness of Utopia is the treble speed for the lower trebles and upper mid
Doesn't Sr 009 have more resolution,Soundstage,bass extension,treble extension and speed?
I would say get a demo to know for sure. Have you got access to both 009 and Utopia? I thought you already had an opinion on the 2 together? I would say get more time with both before you push the money trigger. It is a big spend and only hearing these two will resolve it IMO. Peoples preferences and amp / DAC choices come into it a lot, even how loud they play them as well.
I haven't heard the Utopia yet, but I would offer my opinion on the bass quality of the 009s. I have big horn speaker in my HT system with 12 inch bass units and augmented with a Velodyne sub. So my HT system goes down to below 30Hz and is fast and dynamic, partly as my room is not so big and I am sitting really close.
The bass on the 009 goes as lower, is faster and more textured than my speakers, possibly not as forceful but you get room pressurisation in a speaker system, something very difficult to replicate with headphones. It's character is not as 'bloomy' as a speakers bass maybe? It is different, but still very convincing. It is also NOT one note bass as in some headphones, especially fed by digital. Bass quality is spot on with the 009s IMO, if it was increased in level it would, I am convinced smear the mid range and treble and muddy the soundstage and reduce the 3D image. Remember the ears get fatigue with too much bass and will react by 'closing the shutter' so to speak, i.e. reducing the reception coming into the ear.
An example, I have an Armin Van Buuren track that is very well mastered and has a rubbling and pumping bass line, it flows up and down like the pulse of an elephant for example. It underpins the track and sounds like an earthquake in waves, hard to explain, but on the speaker system it is powerful but not as tuneful. On the 009s I hear the texture of the bass tune, the subtle phasing and pulsing as it rumbled along and at the same time all the rest of the frequency spectrum is working to the max. i.e. the 009 has the uncanny skill to handle both aspects at the same time, like it is no problem, ha ha, what do you want me to do next.
That bass character is a challenge to reproduce in any speaker IMO, and I have tested that track on many setups. The 009 and Carbon nail it, totally. I am saying, the bass is there, and there is tons of information and texture to it, it is not exaggerated or one note. It is something to get used to IMO. The whole stat sound is something to get used to TBH, and for some it grabs them, others just never relate to it, which is understandable as we all have different tastes and expectations of how music should sound.
I listen to lots of genres and bass demanding music such as trance and house music sound great to me on the 009s. Lots of drive and pace, really damb good. I really don't feel any need to up the bass at all. I have done that in the past with digi EQ by around +2-3 db before I finished my DAC tube rolling. But now I feel no need of it. Tyll in his review upped the bass EQ on his Utopia by 5dB I believe.
My other thoughts / theory on the bass output is, unlike a 'normal' house speaker system with 2 or 3 way designs, the 009 and most other HPs are single driver. If that driver has to produce as ruler flat and fast response as possible to provide the illusion of a live music event, it will have a hard time indeed getting loaded up with too much bass energy.
Also 'maybe' folk coming across from V shaped HP's (massive generalisation and not meant as an insult) they may well find the Stax model too different?
I guess no HP will be perfect, relate the live event with the huge dynamic power and 3D image that can be experienced. But the 009 IMO gets me close enough, close enough to forget the gear and track swopping and sit back and chill with it. Sometimes late at night, and putting the 009s on they blow me away to another place, they are that good IMO.
I do also believe they are ruthless at revealing upstream gear, a microscope to what is going on, so much so it demands more investment elsewhere or the owner will never be happy and have to move on....
Hope this helps
. If you want to say the weakness of Stax ? It is not portable, and it is expensive as hell. That is that
....will be expensive
. However, it does seem that being ES, Stax limitatoins has expanded beyond the limitations of Dynamic drivers. But again, nothing is perfect 
