I'm a Cubase user and am happy to diss ProTools any day of the week (especially LE/MP) but I disagree with it sounding 'fatter' and meaner.
The same audio, with everything configured the same (pan laws, no processing or plugs, etc) sounds the same. I use Logic and PTHD at work and with everything the same, you might notice a slight discrepancy or two on a spectragraph but if you can actually hear it you'll cry out in pain when I blow the silent dog whistle
There are many reasons to consider Logic or Nuendo/Cubase or Samplitude (this is usually described as the 'fattest' based upon the fact it had the first 32 bit floating point engine several years ago, and people hang on to that legacy notion, even though Logic and Sonar and Cubase have updated their audio engines at least twice each and match it in every way now). But 'better' audio quality is not a valid reason IMHO, as someone who has used all of these programs.
Why people like one of these over the other is usually down to different interfaces, different plugins and pan law settings, which has nothing to do with untouched raw audio.