Agree with everyone else. I had an artist send a landr version and I thought it sounded terrible. Not only was it smashed, thin, and way out of balance but the stereo field was collapsed to almost mono.
I assumed the clients mix wasn't all that good so I told him I would do one for free just so I could find out where it went so wrong.
He sent the mix and I was blown away. It was a good mix...ten times better than the master sounded with great balance and a wide, deep, stereo field.
Long story short, I've been mastering his single online release tracks ever since. I don't claim to be a mastering engineer by any means but any fool could out-master lander with just a stock plug-in limiter.