1. Accuracy and Reliability – Performs well without reoccurring malfunctions and stoppages and results in consistent, accurate target hits with a 3″ inch hit group maximum or less at 5-15 yards for concealed carry
2. Trigger Press maximum of about 5.5-6.5 pounds – lessens force applied for less movement & better accuracy – and press that is crisp and identifiable (TRAIN to be Trigger Safe)
3. Trigger with short travel distance (a short travel distance increases the speed the trigger can be fired) and easily identifiable and short reset point; Trigger with a smooth consistent press for every shot (less need to transition between presses & make adjustments)
4. Barrel length of 3.0″- 4.5″ for primary concealed carry gun; 3.0″- 3.5″ for subcompacts; 2.70″ – 3.6″ for .concealed carry of .380
5. Sights that are basic & simple (easy to use & see–I like Fiber Optic fronts); fast target acquisition; for my purposes– adjustable for windage; Night Sights for low-light situations;
6. Proper Gun Weight to minimize recoil (I prefer 25 oz. max or much less for carry- but there are tradeoffs;)
7. Caliber match to my needs, characteristics & abilities (consider medical & physical limitations); 9mm is my preference for my primary carry gun (consider .380 ACP for Backup Gun- BUG;)
8. Capacity – adequate for use & feature tradeoffs- usually prefer at least 7 rounds or so (for subcompact) in a .380 magazine for carry or BUG (but can carry a spare mag or 2 sometimes);
9. Ergonomics – Hand Comfort and Grip Fit, controls easy to work and easily accessible; rounded, low-profile;
10. Miscellaneous – Overall Finish, fit, & quality appearance & workmanship; mag release location & function to drop mags freely; ambidextrous controls; accessory rail as required; grip angle; bore axis; competitive market price; excellent customer service with friendly & helpful representatives; ease of disassembly-assembly; Hard Case; want at least 2 mags for concealed carry; Extras (like a third mag, holster, pouch, extended & flush mags); warranty length & extent; safety factors, etc.
You make your own tradeoffs according to your personal goals, priorities, preferences, needs, and use, but take a total system perspective and recognize that there are several overall features, characteristics, and pros and cons to include and then consider them.