I have enjoyed my 357/9mm and my 45/45 convertibles for more than 30 years. At what I consider reasonable ranges, the accuracy of the guns is more than adequate.
For me the biggest benefit is being able to buy cheap 9mm or 45 acp ammo for practice. My practice is hitting an 6" paper plate at various distances ranging from 3 yds. to 25 yds. Since I no longer reload, shooting 38/357 or 45 Colt loads could become cost prohibitive. With bulk packs of 9mm and 45acp I can practice more often at a reasonable cost. Recoil being different, I do shoot .357 loads and heavy 45 Colt loads every so often.