The sound of stereo buss compression has become ubiquitous in today's larger-than-life music. When it's done well it can enhance the sense of cohesion and fullness that makes a recording sound like a record.
When it's done poorly it can make a recording sound bloated, puffy, muddy, muffled, distorted, and just plain bad. The stereo mix presents a challenge to the compressor that is unlike processing an individual track. Its charge is to control dynamics on a wide range of sounds without pumping on the kick drum, muddying the cymbals, burying the snare or losing focus on the vocals.