We are all different, but I never understood WHY Smith didn't market the FIVE inch barrel more? IMHO it's just about the perfect compromise between a too long six and a short, 4". And it balances so nicely too.
They did a run of the .45 Colt M-25-7's and -9's in FIVE inch. Way back 1956 or so, the five inch barrel was an option on the first .44 magnums too. Plus the MO State Police and a few other Agencies ordered some 5" K-38/M-15's at some point too.
Many years back I passed on a 1958 era M-29 that had been rebarreled by the Factory with a 5" barrel. The guy wanted way too much considering it wasn't right. And it had been somewhat abused too. But passing on that gun bothers me to this day. Could have had a great shooter, five inch!