It's an odd thing. As soon as you commit to a certain caliber or weapon you become keenly aware of its limitations and the fine characteristics of the other choices. If you choose a riot gun over a modern rifle such as an AR-15, you become keenly conscious of the shotgun's range limitations. If you choose the rifle you become aware of its lesser hit probability, at close range where it counts. So it is with other sorts of guns--carry pistols or you name it. Your choice becomes a fence, on the far side of which the grass is greener. I suppose that is why some shooters have lots of guns. This gun does something or other better than that one, and the other one over here is lighter to carry than either of those, and so on.
Still, you have to narrow things down at some point. You cannot carry a whole safe full of guns with you, and it is not practical to stock up on ammo in a dozen calibers.
What if there are no wrong choices? In terms of likely threats, either the riot gun or the AR-15 will do a good job of protecting your life, and either the .38 snub or the pocket auto pistol is a good deal better than nothing if you need a gun unexpectedly. Doubtless the gun manufacturers would rather you not think this way, but why not ask yourself whether what you have is generally adequate? If it is, stop worrying about it. You don't need to go shopping.
What you really need to do is get to the range and practice, using drills of high relevance to real world scenarios. Solve any problem that tends to plague your shooting, whether it is a flinch, rushing the trigger, pointing not aiming or whatever. Worry about software not hardware--by which I mean, program your skills. In many cases, where there has been a real need to shoot to defend one's life, the kind of gun used has been the factor that has counted least of all.
And yet that is the one we worry about. Go figure!