You can test yourself like he suggested.
Compare 2 different generation of sound cards ( with different noise floor different dynamic range) and you will know.
I am only saying that what he stated is nothing knew, he is not reinventing the wheel.
Now from how I bad it sounds I don’ t know, and to be honest it is not important.
His suggestion on the equaliser is also nonsense in my opinion.
I honestly don’t really care enough. I like the sound of the OT and don’t really notice any change to the samples that I load on it.
I’m just tired of people saying “bUt ThE cOnVeRtErS!” all the time 
I believe the end of stimmings review, in modern parlance, is called ‘trolling’.
Nevertheless, some valid criticisms, that I only hope push Elektron to outdo themselves.
It’ s good you should not care and be focused on making nice music.
I like the OT and I think it is a great product.
The converter topic is something not everyone is keen on.
I only know that when I sample or record something in my old RME FF400 it does not sound good, detailed and open as when I record or sample using my Metric Halo ULN8 3D.
Now in terms of technical specifications, this is from the OT mk2 manual, it does not say much on the Converter performance.
It only mentions the Digital Signal Noise ratio which is 106 dB on the input and 104 dB on the output.
Digitakt is 110 dB on the input and 108 dB on the output.
Now not a huge difference here,
We cannot do a good comparison on paper with other Converters as a lot of information on the ADC/DAC of the OT are not reported in the manual.
ELECTRICAL SPECIFICATIONS
Impedance balanced audio outputs
Main outputs level: +17 dBu peak
Output impedance: 440 Ω unbalanced Digital S/N ratio: 104 dB (20–20,000 Hz)
Headphones output
Headphones out level: +17 dBu peak Output impedance: 55 Ω
Balanced audio inputs
Input level: +17 dBu peak
Audio input impedance: 21 kΩ
Digital S/N ratio: 106 dB (20–20,000 Hz)
Unit power consumption: 7 W typical Compatible Elektron power supply: PSU-3c
Check this video as well https://youtu.be/ZpjNGDzyJgw
About how good a hardware 16-24 bit sampler sounds. I wonder how much experience do people have with other hardware 16-24 bit samplers? Also keep in mind that the Octatrack is Elektron’s flagship model.
Funny that Stimming don’t mention the Analog Heat. For him this could be a simple solution instead of building his own thing.
FTFY
I guess thats from inside the OT?
I have a fair bit, I know what I’m doing, I compared the OT capturing a music loop with broad frequency content, I compared the sample to the source and the other samplers (Toraiz SP16, Blackbox, Deluge, MC-707) the sound quality was fine, no obvious artefacts, very transparent (more so than the SP-16) but I had time stretch turned off, no fx, correct gain structure - which anyone who is interested in assessing sound quality should do before making statements about sound quality, IMHO.
Now, I’m 51 so my hearing is not perfect although pretty good for my age, my monitoring setup and room are not ideal, though better than the average consumers. But I’d think that it would be safe to say that I’d be able to notice any dramatic difference in sound quality, given that I can definitely hear the difference when TS is on, fx are loaded and gain is set too low - which is exactly what I think most users who mention bad OT sound quality don’t take into consideration.
Of course there are degrees to what is good sound quality, what is acceptable, and what is bad, these are different for different people, but for me transparency is what I look for, I want the sample to sound the same to me as the source, which the OT can do, for me.
My uneducated view is the OT is flat, but other devices like the DT or Toraiz spice up the sound to create more crispy brittle hifi, further enhanced by the likes of the DT FX.
I would quite like that sizzle on the OT too, but flat is also fine to work with when you have ABCD FX loops.
Comp and filter with a little filter distortion or comp and eq with a little high shelf boost on master track should easily get you in similar territory.
I like using the DJ EQ to do this.
Its very obvious that this thread is a staged conspiracy to sell us the ah. Involved are elektron, the new elektron shareholders, some users and moderators and stimming ( and probably klaus schwab). Also soon he will say sorry due to chip shortages i‘m not able to build my thing but you can buy the ah ( cough).
Btw since years i think about the ah as something i should, could get.
( stimming loves the pure tanzbär sound, me not mostly. I think it would be nice with ah.
I have almost no knowledge, get ok results via a4 or fusion box and should profit from ob but…)
I just played an audio recording of myself on buffer track on my OT, reading your comment out loud.
I sounded shallow and unconvincing, like Steve Buscemi selling a used car.
Then with a simple Thru routing to an Analog Heat, the same recording was transformed into Morgan Freeman. Graceful, authoritive with a hint of Southern musicality.
Nice. Ok convinced ( to think about it more often) No, I was impressed by a lot of ah videos. Last time some weeks ago in the current sounds thread a kick from adam jay where I thought wow this is the perfect deep punch but not stressfull kick. But I know its 95 % knowledge, gainstaging etc and only 5% ah. And there would be things of higher priority for me, like a table, more patience etc. But ah impresses also as a quick drumsound mangler.
Interesting or strange: Yesterday I saw in the yt comments to that video stimming answers what he used on his laptop to enhance the ot sound before he used his own thing. It was a simple bitwig effect chain (he said because he could use a low spec pc ( why?)) . As far as i read and saw, bitwig really is not known for the most hi fi effects. It needs a lot of knowledge and modulation to bring them alive i thought. Mostly the reverb, the saturator could be a secret weapon probably.
So…there’s a thread “current sounds coming from your gear”…
I will wager if people stopped listing what they used, you’d NEVER be able to tell whether there was an OT or whatever gear in there. Pretty much squelching the sound quality issue.
Me I’m gonna stop listing what I used and just put number of pieces used instead. OT will be in there sometimes and I challenge people to point it out 
^This
I once took a VoiceOver/narration/voice acting class at a local theatre. The final project was to record myself reading out loud ad copy of our choice from any magazine, in 30-60 increments (three total). I chose to read a credit card, an insurance ad, and financial management company ad. When I presented mine to the instructor, he was perturbed, and said, “what are you going for here, you don’t sound all that different than you speak in person?” I said, "I want to be the next Morgan Freeman, the voice of “truth,” the voice that, when you hear it, you automatically say, “yes, I believe this guy.” He wasn’t satisfied! Oh well.
The sound degradation was always apparent to me but it never bothered me! Why not? Bc it sounds good enough for my small insignificant music.
It would bother me if i would ever manage to make a non-mediocre track on my OT, a genius level piece of music that would change lives of millions now and millions in the future and if it’d supposed to sound as hifi as possible! So, basically, it will never bother me!
Imo ppl should put things in perspective, realistically!