I only own two handguns I purchased partly because of capacity -- a S&W M&P (semi-auto) and it's little brother the M&P Compact, both in 9mm. It's just nice to have that option. I have purchased the rest of my handguns with other and different criteria in mind. I own two "evil" rifles that I purchased with capacity in mind but the rest were also purchased with different criteria in mind. I purchased my small selection of shotguns without much regard to capacity, other than wanting more than a single shot.
Jim's Rules of Carry: 1. Any gun is better than no gun. 2. A gun that is reliable is better than a gun that is not. 3. A hole in the right place is better than a hole in the wrong place. 4. A bigger hole is a better hole.