I have them on my one trem-equipped guitar. They do seem to make the tuning more stable when you use the trem, which is why I put them on, and theoretically cut down string breakage (I haven't broken a string in probably 15 years, so this was not a consideration for me). They do change the sound of the guitar - seem to "smooth out" the tone a bit, making the sound just the smallest bit less dynamic, at least in my experience.