Joseph: My son who went to Chofetz Chaim has a beard and does not wear peyos behind his ears. My second son (not exactly a “Brisker” but learning in a similar type of yeshiva) does not have a beard but wears peyos behind his ears.
The big difference is that my older son started helping and learning with teenagers as soon as he was able (aged 22 now 26) while my other son is still involved with his own learning and not even thinking yet about harbotzos torah (and he is 24).