The "hammer snag" issue can be easily overcome by technique. Put your thumb over the hammer as you draw the gun.
I almost never take gun advice from cops since most of them consider it "that thing" on their belt, though there are exceptions. But, the idea that "generations of detectives" did something, most of whom were never gun afficionados, does not convince me of anything regarding guns. Likely, their choice was dictated by convenience, bureaucrats, and budgets. Jim Cirillo, Bill Jordan, and Ed McGivern spent quite a bit of ink and energy combating the bureaucratic mindset.
I choose 44 Special because its performance in personal defense is well known. Heavy 357 Magnum revolvers are good too, and you can buy an eight shot snubby from S&W.