For the last couple of months, I noticed the crutch end of my end pin (a standard heavy steel adjustable one) was starting to wear out. It would make squeaking noises whenever I shifted the bass. The squeaking noises actually carried through the amplifier so I had to be really careful when playing.
The simple solution was to buy another crutch end but around the same time I read about Atomic Endpins. So I did both. I contacted Johnny and ordered an endpin and I replaced the crutch end. The squeak went away with the new crutch end and I sort of forgot that I had ordered the Atomic Endpin until it came in the mail.
I pulled my end pin out and put the Atomic Endpin in and something happened that I didn't expect: the bass got about 10-20% louder and more focused. I play with gut strings and frequently play unamplified so a 10-20% increase in volume is nothing to sneeze at. The additional focus is also very welcome.
It appears the extra weight of the steel endpin really damped my bass. I've gone on to order Atomic Endpins for my other basses now as well. It's probably the single best adjustment I've made to the bass other than maybe going with gut strings. So these things are way more than just snazzy looking--they really make a difference to the sound of the bass.