I prefer to play pure nickels strings, preferably round core (like Pyramid Classics Pure Nickels/Fender Classic Cores, these Fender's have hex core), and bullet ends are said to add a little sustain. I don't know, honestly. For sure they look cooler than regular ball ends, however who sees that? I have cross compared them with the regular Fender Pure Nickels 150R, I didn't hear any noticeable differences. But maybe that's just me :) The 150R's are usually sold at a lower price, so i'd opt for these bullet ends only if your ears are better than mine or if you just dig the aesthetics :)