In Hawaii everything is 10 rounds for pistol. I primarily shoot Open with a 2011. But, I don't only shoot at home I go to some major matches on the mainland where there is no limit on mag capacity. That is why I and others go with the 2011 or other "fat" guns. I do have a single stack open gun from the olden days but never use it anymore.
If I were shooting mostly single stack I would go with a 1911 in .40. That way I can shoot in SS (major and minor) and L-10 and Ltd (in banned states).
In mag restricted states, everything is ...10 rds. No one has an advantage in capacity. Just my 2 cents.