++ on Rod Jenkins tab. The tendency is to buy a tab that is too large, which leads to poor releases and a scuffed face. I have normal sized hands and use a medium. It will seem too small when you put it on, and your fingers will stick out the front. It might sting your fingers if you're not releasing correctly. That is a blessing in disguise, however, as the sting will teach you to release correctly, and you'll end up shooting better.
A regular tab is just a flat piece of leather, and can be trimmed to fit. Not so much with the Safarituff tab, which is customized to fit a certain size of hand, so it is important to get one that fits right. Of course, Christmas is coming and you can always give the ones that don't fit right to your friends.