I'm pretty much a fan of very small BBD range point and shoot handguns as a SD layer. And kinda like real estate, I tend to think the three rules might be location, Location, LOCATION with the addition of again. Again, AGAIN.
When under stress being able to relatively accurately place multiple rounds in a fairly compact grouping is essential.
I have a fairly wide range of small handguns in 22LR, 25acp, 32acp and .380. In the little 22LRs I have the Bobcat as well as the Taurus Annoying Cricket PT-22 Poly. Both have pretty chubby grips but that is an advantage when it comes to control under stress. The Taurus might have a slightly better grip in my hand than the Bobcat and both have been equally reliable BUT only when kept clean and using the brand and type ammo they like. The Taurus has been slightly more forgiving when it comes to variety than the Bobcat.
In the small 25acps I prefer the FN & Colt designed vest pockets that have the safety as well as grip safety over those that have just one safety like my Baby Browning and others. The Colt's safety/slide lock is better in clearance issues as it locks the slide with the port fully open. The FN safety/slide lock is designed to hold the slide open at the takedown point and so is easier during general maintenance. I've honestly had almost no failure to feed, fire or eject though with either so my FN seems to get to go WalkAbout more often than the Colt.
In little 32acps the Tomcat is just about the same size as the Bobcat but with a slightly wider slide.
In .380s I have the S&W Bodyguard, Remington 380, Beretta Pico and Ruger LCP as well as the slightly larger but still compact Sig P-230 and P-290-RS. (An EG Makarov also in the same size/weight category as the Sig P-230)
The PT-22 holds 8+1 rounds while the Bobcat is 7 +1.
The Vest Pockets are 6 + 1 rounds.
The Tomcat holds 7 + 1 rounds.
The smaller .380s are 6 + 1 rounds.
In my hands and using point & shoot at BBD ranges, control and repeatability is as follows.
The Taurus PT-22 with its chubby and slightly longer grip is the easiest of the whole bunch when it comes to control and repeatability.
The Bobcat and Vest Pockets come next.
The big chubby grip on the Tomcat also really helps with control.
The .380s though are really the outlier. The .380 is a big enough step up in recoil and the grips pretty short and in the case of the Pico really, really slim that control and repeatability (again in my hand) becomes a noticeable issue. Groupings spread out significantly compared to the others as well as return to POA and second shot.
However, regardless of what other handguns I might carry, it's almost certain that one of the little gems will be in my pocket.