Chregg
"I use the UAD platform and the difference in RTAS vs. VST of the same plug is clearer and small changes in the knob settings can be heard in RTAS less so in VST. I have file tested this and there is a difference in the files in the mid to upper frequency range. " Thats quite interesting that, hate to drag you back into this, but what kinda differences where you seeing/hearing between the files
Middleman
I use the UAD platform and the difference in RTAS vs. VST of the same plug is clearer and small changes in the knob settings can be heard in RTAS less so in VST. I have file tested this and there is a difference in the files in the mid to upper frequency range.
From my experience it is a waste of time to compare DAW platforms without taking into consideration the primary influencer of the sound which is the plugins used to develop a mix. Another area which is never debated is how one DAW handles the audio driver versus another. This alone can skew your listening results even though the files of two systems can match.
Bowing out now because I have a feeling this old and worn out debate is about to tumble into the realm of my DAW is better than your DAW.
What you experience is is because of phase shift and quality degradation of the RTAS plugins. RTAS do not sounds better actually it perform worse both in audio quality, CPU use, multi threading and latency. RTAS is in 24bit only. VST float in 32bit or 64bit.
New AVX plugins float in x64bit and will sound and perform much better then RTAS.
AU-plugins, OSX audio drivers and OSX over all perform less then PC and VST. MAC and OSX is not a very good multimedia platform that you might think.
That is why the big turn in the multimedia industry last years (Music, FILM, animation, Photo) toward PC platform. As far as I know AVID has put their main resources making PRO TOOLS 11 x64 work and perform best on Windows 7/8 x64bit platform.