I used to use brass for ease of installation etc, but tie-on with serving material or floss has too many advantages: wont scratch your bow when unstrung and getting moved around, won't scratch your face if you anchor close, won't scratch fingers if rare instance of shooting w/o a glove or tab, less risk of damaging serving (though must also be judicious when gluing tie-on nock points!) and my favorite part, if tied to the proper tightness they don't necessarily need to be glued and can always be adjusted up or down to fine tune quickly. I hate fussing with nock pliers once a brass nock is in place. A spool of serving material also lasts a long time, through many strings and the different ways to tie on a nock point are numerous and you can more or less learn/ tailor the way that works for you.