The only tone change Ive noticed k3 coating gives is little more brightness and harmonics are not as easy to do. Compared to the sunbeams which are what neons are said to be but just with coating added. Thats the only sound diff to me. The neons and sunbeams have same low bass articulation level which imo is better then most strings included my prev fave strings. So yeah the coating does give small tone diff to me. Little brighter and touch harmonics are not as easy to do as the on the uncoated version (sunbeams).