I've owned a Walther PPK in .380 caliber for about 15 years, buying it used at that time. I would shoot it periodically at the range and occasionally carry it, but never on a regular basis. I liked the small size and flat profile of the PPK, but was not overwhelmed with the ballistics of the .380 caliber, preferring something larger like 9mm, .40 or .45. I felt that .380 was fine for a backup gun to be used as a last resort, but not as the primary gun. And the Walther wasn't perfect as a backup, being heavy (21 ounces) and a little large for pocket carry.
Recently I've been reading about the popularity of many new small, lightweight .380s coming onto the market, and was particularly impressed by the reviews of the Sig P238, an aluminum framed single action gun with thumb safety that looks like a miniature 1911. I often carry a single action 1911 in cocked and locked condition, so I was not put off by that mode of carry on the P238. I recently found a slightly used P238 at a fair price, so I bought it.
I am very impressed with the P238 so far, and feel that it is greatly superior to my baseline, the Walther PPK. The big advantages I see with the P238 over the PPK are:
1. Lighter weight, under 15 ounces for the P238 compared to 21 ounces for the PPK - easier to pocket carry.
2. Shorter barrel than the PPK, again aiding pocket carry.
3. Better trigger - The P238 has the same 8 pound crisp pull on all shots, while the PPK has a very heavy DA first pull, making it hard to hit with that first shot.
4. Better sights - The P238 has large night sights (standard on gun) while the PPK has miniature sights that are hard to see.
5. Less recoil - The PPK has a blowback design with the barrel fixed to the frame, so recoil is sharp and strong, while the P238 has an unlocking barrel like larger semiautos, which softens recoil.
6. Lighter recoil spring - The PPK has a stiff recoil spring and is hard to rack, while the P238 spring is noticeably lighter and easier to manipulate.
So I think my P238 has definitely replaced my PPK in the .380 role, and is even a contender with my S&W 642 revolver for the backup/pocket carry role because it is shorter, flatter and easier to conceal than the revolver. It also holds 2 more rounds than the revolver.