I carry a Springfield double stack 1911. She ain't the prettiest gal at the dance, but she does sing twice as long as the single stacks.
Seriously, if you can handle the grip girth and weight, the extra rounds are worth it. Just be advised that parts for double stacks, other than factory replacements, are nigh impossible to find. If you want a good, basic carry pistol, the double stacks are fine. If you like your Gucci gear, go with the slims.