Yes, size IS important - when you're choosing a handgun for everyday carry (EDC). Jeff recommends first defining your "mission": what you intend to do with the firearm. You need a gun that fits your hand. It has to be one you can carry comfortably, so you don't fidget or do other things that tip off people around you that you're carrying a gun. A full-size pistol like a Glock® 17 is difficult for the average person to keep concealed. Compact pistols, like the SIG P320, balance size with performance and mag capacity, making them popular EDC guns. The good thing about subcompact pistols, like the SIG P365, is they're easy to conceal; the downside is they can be difficult to shoot. "Micro compact" pistols are super concealable, but they're also very challenging to operate and come in low-powered calibers that aren't the best for self-defense. But remember Jeff's Golden Rule: Having A gun is better than NO gun at all!