Knife selection, as with a firearm, is a personal choice. What is comfortable one person may not be for someone else. The main thing is to get something you are able to use, and use it well in an intense situation.
Don't listen to the traditional advice that says you need a minimum 5 inch blade, that's nonsense. If you know how to use it, a smaller knife can be just as effective. Just because the blade is smaller doesn't mean it won't do as much damage in a self-defense situation.
