The 9mm Smith & Wesson Shield is a great carry gun. It’s perfectly sized to balance concealment and control when shooting. As a single-stack magazine pistol, it’s flat, so it’s not only feasible but comfortable to carry inside the waistband. Depending on your clothing style preferences, it might even work as a pocket gun.
However, if you like big bores and you cannot lie, there’s always a Smith & Wesson Shield 45. That’s more of a handful with felt recoil as it’s still a small and light pistol, but it’s launching a fat and heavy bullet. Physics is physics, so you’re going to feel that a lot more than its 9mm sibling. For defensive use, the “feel” isn’t a huge factor, as you won’t notice it during a self-defense encounter.
There are two distinct downsides to bigger recoil. First, a heavy recoiling pistol just isn’t all that much fun to shoot. If it’s not fun, you’re not going to choose it for your next range outing, and your skills with your carry pistol will suffer. Second, even if you tough out the pain of more significant recoil, the associated muzzle flip is going to make you slower at delivering aimed follow-up shots.