In addition to providing top level playability, a good setup can and will improve the tone of your instrument. Now what it won’t do is make your instrument sound like something it’s not. In other words, while it will bring out the best and improve upon the characteristics of your stringed instrument, it will not radically change the voicing. Will you hear a difference? If you have a good ear for tone, you will hear a difference but mostly you will feel it when your play.
With that said playability is the place that has the potential to undergo a night and day change. This really depends on how well your instrument is setup to begin with, but an average player should notice a nice improvement once we are done with the instrument setup.