I own a G21SF and it holds 13+1. Unless you live in CA or somewhere you can only get the 10 rounders. I'm a .45 guy myself so my opinion is already biased on which one you should get but as far as standard 21 vs 21SF is dependent on your comfort level with the grip. Many people say they don't notice a difference, I certainly do and that's why I went with the SF version. I suggest that you find a gun show or store or a friend or even someone else at a local range with a regular and/or an SF model to see which you like better. Good luck with your decision.