The majority of competitive shotgunners around here use in-the-ear protection because they find the headphone/muff-type cumbersome and interfere with their gun's dynamics. It depends on your stock fit and height of your cheek bone. Try mounting your gun with the muffs before you buy them.
I use muffs only for pistol shooting. At the rifle range two days ago, and was the only one without muffs. It may be a regional shotgunning preference, in the sunbelt we're not used to wearing ear muffs. You're probably very familiar with them in Minnesota.