That's because I didn't intend to proof that this or that is superior or inferior. What is though quite easy to proof is that they sound different, because they take different routes for the tasks they have to perform, that is conceptually, in programming and such. If anyone wants to take the bourden of testing go ahead.
So if you do that carefully, only using repeatable and comparable tasks etc etc you will get to hear discernable differences. And this is where subjectivnes comes into play in different regards: What is the working purpose, what sound do you go for, what routes do you take to achieve that.
I think there is one major false reception of what makes working in the digital domain different compared to analog, like the idea that it is like taking a clean path (a little bit like the misconception when displaying digital sinus in a stepped form, which is simply not what represents a bunch of samples, but a trick to visualize the concept). If an anlog console has to send its current through different stages to let it reach its destination properly, that is where it necessarily is getting processed, which also means getting altered, no matter what. Working the same path in the digital domain is by no means different by its approach, bits must be delivered along a certain path to reach their destination, whereby they necessarily are getting processed, and altered - more or less. And that is in fact achieved in different ways, just like analog consoles are built different and sound different - so do diffrent digital consoles. DAWs are just no exception. Even different CPU architectures could produce different results when you would bit compare the results - but don't try this at home, you would need to setup complete insane amounts of processings to make their different handling of rounding erros result in different bits. But as said to make different programming routines, different use of libraries and such (which occure with every single step of delivering the bits), visible in your results is quite easy, if you want to take the time to do so - I am done with it.
That said DAWs do not sound the same, wether it is by purpose or because someone needs to take a shortcut here and there. The less necessary those shortcuts become, because of increasing processing power on the machines generally in use, the less they differ in this regard. Still there remains different use of libraries, integer or float (anyone for integer still, 'cept Bob Lentini?), programming skills (yes, absolutely!), but all in all it is becoming more and more a matter of taste, which is an absolutely fine thing. And then there is your DA interface (getting better and better), yes, and your AA interface, which is your hearing ability, your fitness and what not.
A good performance, engineering skills will do their own part in levelling out things in comparision for sure.
Know what, I do like tracking drums with a Tascam 234, and if I don't like the cassette sound I just use their input gain and the routing - for the sound. I do master through a Studer console, and if I don't get where I want I stay completely ITB, which has become very pleasent these days.
To end that with a proposal for a short test route to take: Today I got quite a funny expression (see Ry Cooder on his first record) on my face when - because I sometimes forget to do it beforehand - while composing in Live I switched the /O of a sampled Grand from Live's Master to direct /O on the Mytek I used, wow, that blew me, since the Grand was the only track I had left on the Master! Try that with Samplitude, you will not be able to hear any discernable diffrences. That's why I always end in Samplitude, and yes, (some!) of the others can do this too, but I use Samplitude for a lot of other reasons. Trust in the devs is one among many - I tend to believe they still love their sound more than features.
And Tim, sure this is all in your head, since hopefully that is where your ears reside ;-)