If you play with styles (I don't allways)
Then the Style is about 60-70 % of the performance
So yes, when playing with styles, a good style makes you sound better.
And as Eric and Gunar say, good styles inspire..

But does it make you a better musician?
Well, i think better style quality makes the crowd believe you are a better musician. Unless you play without styles or midi files, just piano or organ. People might recognize the musician in you better. But that was not the question.


So yes, i think styles quality really matters.