I said some years ago:
... smaller handguns are more difficult to shoot well than larger handguns. A good example may be found in the Glock handgun series. The Glock 17 is a full-size handgun; the Glock 19 is a compact version; the Glock 26 is a sub-compact, highly concealable version; and the Glock 34 is an extra-long-slide competition version, with the same frame and grip as the Glock 17.
. . .
Obviously, one's hand can grasp the full-size grip of the G17 or G34 better than the slightly shorter grip of the G19, and any of those three better than the severely abbreviated grip of the G26. That, plus the longer sight radius of the larger models, makes it easier to shoot them more accurately than the small G26. On the other hand, the latter's shorter grip and slide make it much easier to conceal than its larger siblings. If concealment is a priority, one has to live with the disadvantages of smaller size.
There's more at the link, including photographic comparisons.
The size factor in handgun controllability is very real. During our recent Blogorado weekend, I had with me several revolvers, including two snubnose versions, one in steel, one in a much lighter material. Several shooters tried them. The universal finding, without exception, was that the small snubbies were much more difficult to aim (due to their diminutive sights), and control in rapid fire (due to the greater recoil transferred to the shooter's hand), than larger, heavier, full-size revolvers or pistols. I'd go so far as to say that shooters were only half as good with the snubbies as they were with larger handguns ("good" meaning the ability to rapidly and consistently hit their targets). The lighter snubby also proved slower and more difficult to control in rapid fire (i.e. recovering from recoil, getting the sights back on target, and firing another round) than the heavier, steel gun, because the former moved more under recoil. Effective range was halved compared to full-size guns; to get good results, the shooters had to be within 5-7 yards of their targets. Longer ranges degraded shooter performance very noticeably with the small guns.
That lesson applies to small pistols, too. Tamara has just addressed the subject for Shooting Illustrated.
So, ... what are the downsides to carrying one of these handy single-stack 9mms?
Well, for starters, they’re harder to shoot well than their larger kin, and for numerous reasons. The shorter sight radius is one, but probably the least significant. More importantly, the stubby, small-diameter grips of these guns generally mean a two-finger grip with the dominant hand and the support hand is unable to provide as much clamping force as it would on a larger gun. With less grip on the gun, small errors in trigger-finger placement can be dramatically magnified.
. . .
The small grip on a single-stack 9mm also affects recoil control, obviously, as do the lighter weight and shorter barrel. Multi-shot strings are going to be noticeably slower because of this. I’ve seen shooters turn in amazing performances with little guns like these, but much like the J-frame revolver, a mini-nine is not an easy gun to run well without a lot of practice.
. . .
In reality, the [Glock 43] is a lot closer, capability-wise, to a J-frame revolver or a pocket .380 ACP, and that is going to drive my tactics and decision making. In a scenario such as one with a lunatic in a movie theater or mall, the little G43 can’t engage from ranges where I’d be perfectly comfortable making a shot with a G17. They may both say “Glock 9x19” on the slide, but the gulf in capability between duty size and pocket size is broader than some people realize. The armed citizen who carries a single-stack 9mm owes it to him or herself to know exactly what can or cannot be done with it.
There's more at the link. Highly recommended reading.
I entirely agree with Tamara. I, too, pocket-carry a small single-stack pistol on occasion (either a "micro"-sized Ruger LCP, or the somewhat larger Springfield XDS in 9mm. or .45). I don't like the recoil of the LCP at all - despite its low-powered round, its diminutive size and weight make it a handful to control. The XDS is, in my hands, very ergonomic, much more so than its competitors (although others prefer them - it's all about how the gun fits you). However, I'm under no illusions that the relatively small XDS will be as easy to handle in a gunfight as a larger handgun, such as a Glock 17 or 19. As with snubbie revolvers, with the XDS I'll need to be closer to my target to be sure of my shot, due to the greater difficulty in handling and controlling the smaller, lighter weapon. I might take a head-shot at 15 yards, if I had to, with a full-size handgun; but I wouldn't be nearly as confident with a pocket model. Half that range would be more like it. (Yes, I used to make such shots on paper targets at double those ranges, without difficulty; but age catches up with one's eyes and reflexes . . . )
That factor also explains why I like a pocket pistol in .45 ACP, as opposed to 9mm. Sure, the .45 recoils more, and is harder to control; but in that size of pistol, so is the 9mm., compared to a full-size gun. If I know I'm going to be slower in recovery from a shot, and slower to make a second accurate shot, why not hit my target the first time with a bigger, heavier round that may do more damage? That way, I may not need a second shot quite as badly! Yes, I know that in terms of modern ammunition, the performance of .45's and 9's is relatively close; but there's still the factor of bullet momentum (scroll down at the link to find the relevant section), which favors the .45, plus the fact that the technology making 9mm. bullets more effective does precisely the same for those in the .45. To my mind, if I know I'm going to experience controllability problems with a smaller pistol, I'd rather fire a round that will do the most harm on the other end, giving me more time to regain control and be ready with a follow-up round. YMMV, of course.
If you choose to carry a small handgun as your primary weapon, you should be aware that you need to practice more often with it than a larger weapon would require. Without such practice, your skills with it will deteriorate more quickly, because of its inherent control issues. I'm not knocking small handguns in the least. They have a very valuable place in our battery. However, we shouldn't be blind to the skill and consistent training needed to use them effectively.