Anyone who has actually properly listened to the various units will recognise there’s very clear sonic quality delineation between the range, it’s by design, and Apex doesn’t fundamentally change that.
Problem is some people just judge based what they read about power supplies and chassis differences and just guess without having actually heard. 
While a fair concern, I don’t think people should be overly worried.
If I had a budget of $10k and a choice of buying a used Bartok for $10k - or saving up for Bartok Apex at $20k+ in the future, I’d enjoy the non-Apex now (we shouldn’t forget that the Bartok just got an upgrade to the v2 firmware, which is pretty significant in its own right).
Could you please be kind enough to explain me the technological differences between the 3 Apex DAC?
And listening differences between Rossini Apex and Vivaldi Apex, and if possible with the volume and RT of the room where you listened and compared those 2, and speakers.
Kind regards
Thierry
May I suggest you start with carefully reading Stereophile’s recent Vivaldi Apex review where dCS comments directly on the inherent difference between the Vivaldi and Rossini.
As for the Bartok and Lina ranges, there are plenty of posts on the forum for you to catch up on, I sure you’ll enjoy reading it (rather than me interpreting for you 
)
ps: By the way, I own both the Vivaldi and Bartok, and hear them side by side everyday of the week 
Well, of course it has! That’s what new models do.
I think someone said this higher up the thread, but the current Bartok is still a helluva DAC. I’m reminding myself of that fact, after all the consternation of the APEX upgrade price (which for me is 60% of the original retail price of the Bartok).
Thanks for Stereophile review and Jason is part of people I “trust”.
I just recall that I listened to the Bartok, and I am interested by Apex in any DCS DAC 
Difference between Rossini Apex and non Apex were pointed to me by people that I “trust”, but they do not live close to me.
And OK to @Anupc but who does not answer the question about the room But I am sure that with such gear, you have a perfect RT!
But sorry, I trust very few people on forums, in fact, I trust no one for listening sessions, as most people spent fortune in audio gears forgetting that 50% of what they are listening is their room.
Kind regards
Thierry
Quite right! At the end of the day, you have to trust your own ears, not someone else’s.
If it helps re: the room, Thierry — I spent the last year with:
Bartok 1.0
Bartok 2.0
Rossini 2.0
Rossini Apex 2.0
…and headphones ONLY:
Susvara
Abyss Phi TC
Audeze XC
Meze Emprean
DCA Stealth
Raal Requisite SR1a
Stax X9000
…and some more that I’ve probably forgotten. All via a series of very good headphone amps.
No room in the equation. Just no room for speakers.
The differences between the different dCS DACs was obvious — to me at least. And large enough to take several thousand dollars out of my account 
Precisely!! Which is why you should go listen for yourself at a dCS dealer and compare the range, rather than suggesting the range is fuzzy or asking for my room response measurements which will have zero meaning to anyone else. 
I have no doubts about listening improvements with the DAC you mentioned with your headphones!! And nearly for sure with good speakers in a good room too…
To summarize my main questioning:
Kind regards
Thierry
If you know a DCS dealer that have a good room, just tell me…
Email dCS, I’m sure they can point you in the right direction 
IN MY OPINION, if you are right about zero meaning for any one here, this maybe quite a problem for people spending quite important money in audio gear…
I have several audio rooms (I know, I am lucky). For example, one is about 80 m3, with a stable RT of 0.3s between 200 Hz and 20kHz, bass resonance at 35 Hz is handled by tuned bass traps that lead to a quite good, but not perfect, decay.
Kind regards
Thierry
I had Bartok listening session at DCS official dealer in Paris. The room is not bad, but quite far from what I expect to listen to a 32000€ DAC.
I’m sorry, but none of what you’re talking about is going to help you immediately tell whether you will be able to hear a difference between the dCS range of platforms. dCS dealers have been picked over many years to be able to demonstrate the platforms. Whether you personally can perceive the difference or not is entirely upon you and only you.
And that is going to be true of any venue.
50% of what we listen to, is the room.
Believe or not, know it or not.
If someone here explains his room characteristics, his setup, then I will start to trust him/her about his listening experiences. This is the only reason of my question!! I am not an acoustic inquisitor!!
But if on a DCS forum (I am new here), you tell me that most people do not care to their room, well, I will try to borrow those DAC to get them in my rooms.
@PaleRider Right!!
Kind regards
Thierry
Read to get informed, but listen for yourself to make a decision.
Sorry, where did you read or get the impression that dCS forum people don’t care about rooms?? 
(I suspect your mind will be blown if you know the extent some have gone for their rooms!)