Typically I buy a gun because I want the gun, not because of how many rounds it can hold. I see capacity as more of a side benefit to some purchases more than anything else. For instance, when it comes to pistols my only high capacity gun so far is a Browning Hi Power, and I didn't buy it because it was a hi capacity gun. I do own an AR and an AK, both with "normal capacity" 30 round mags, but that's about it.
"Si vis pacem, para bellum" - If you want peace, prepare for war.