bapu
So.... John's assertion may be wrong?
 
Who'd a thunk it?
 
Well, me for one. I know for a fact that I can listen to any of my mixes and on one day I think it's on the brink of brilliance and on the next it stinks of silliness. The exact same mix.

John

sharke
None of these "DAW X sounds different to DAW Y" claims are ever backed up with science.

They shouldn't. I agree.  But I did hear a noticeable difference in favor of Sonar. Please don't  ask me why.

Vastman
There is a HUGE amount of confirmation and expectation bias operating within each human brain... 
There is also a lot of unique aspects to each daw, like Sonar's PC...
Isolating all the values/normalizing them/double blind study is all that is valid.
The rest of the comments are rubbish

tenfoot
 
This is almost certainly a case of perceived rather than actual difference - a combination of a couple of cognitive biases such as confirmation bias combined with the contrast effect. It is worth reading up on how our brains work when we think we are making critical judgements. The shortcuts we take are called heuristics and they are truly fascinating. Heres a list if you are keen:
http://en.wikipedia.org/wiki/List_of_cognitive_biases
 
A blind study is really the only way to know for sure. The vast majority of credible blind studies done in the field of audio are revealing as to how prone to errors of judgement we are. Good examples are the  comparison of cheap vs expensive speaker cables (which not that surprisingly  found that no one could hear any difference greater than chance) and MP3 vs uncompressed audio, which more surprisingly also found that at higher bit rates there is no perceivable difference. The results of a study at Mcgill University
 
http://www.music.mcgill.ca/~hockman/documents/Pras_presentation2009.pdf
 
Brando is right - it is something far more subjective. In short, we love Sonar so it sounds better:)

Doktor Avalanche
ASIO bypasses MS code layers allowing the driver manufacturer to write their own stack instead to access the HAL (Hardware Abstraction Layer) or even bypass it. It's a way different beast to WDM.
If your WDM driver performs better you are most likely comparing to a badly written ASIO driver.
If you check the Windows 10 thread, MS confirms ASIO will still be the best experience for DAW's, even though it originally came from Steinberg and not them! 

bitflipper
My first instinct upon reading the opening post was that this might just be the result of your unfamiliarity with Samplitude. That would my assumption if it was me - that I was committing some noob mistake.
 
As you're well aware, loading a stereo wave and playing it back in its original file format without any processing (not even volume adjustments) should yield exactly the same results regardless of which DAW you're listening to. Pan laws do not come into play.
 
You could export the wave file from each DAW and perform a null test. If they null out perfectly (as they should) then you'll know with certainty that it's expectation bias at work. If they don't null, then there's been some kind of inadvertent processing applied, e.g. wordlength reduction or accidental application of dither.