No pistol round is “best for self-defense;” that distinction must be reserved for rifle rounds. Having said that, I think the available data supports the idea that, for pistols at least, the 9mm round is adequate for self-defense, but not any better than that.
In my last post, I discussed why a 1911 might be called a production model or a semi-custom model. I’d like to take that further and point out the things you are likely to get in a semi-custom that you won’t in a production model.
The makers of 1911s all fall into three general groups - production, semi-custom, and custom. What is it that differentiates the groups and why should you care? The most significant and obvious difference is the cost.