The CSX E-Series is Smith & Wesson's metal-framed micro-compact 9mm. It pairs an aluminum alloy frame and stainless slide with a hammer-fired single-action trigger and an ambidextrous thumb safety, and it weighs 19.7 oz with its flush 12-round magazine. It is for the shooter who wants a small carry gun that runs like a single-action pistol, thumb safety included, rather than another striker gun. The box also holds 15- and 17-round magazines and a grip adapter, so the same pistol can run as a compact.

The FN Reflex MRD is the closest match in concept, an internal-hammer single-action micro-compact. It is lighter and $23 cheaper, but it holds 11 rounds and lists no manual safety. The Sig Sauer P365 X-Macro matches the capacity of the CSX's longest magazine in one fixed grip with no adapter, at 21.5 oz. The Springfield Armory Hellcat Pro OSP has a 3.7-inch barrel and a longer grip, and it costs $29 less. All three, in the versions compared here, ship without a thumb safety.

Buy the CSX E-Series if you want a thumb safety by choice, prefer a single-action trigger in a carry gun, and like having one pistol that works as a micro-compact on weekdays and a compact at the range. Skip it if you want no safety lever and less weight; the FN Reflex MRD gives you the same internal-hammer idea for less money.