The model 57 .41 Magnum will forever be an "also ran" to the model 29. The original idea was to introduce a .41 caliber POLICE cartridge that had the bullet size, weight, and energy to be more effective than the .38 Colt/S&W/S&W Spl.
Much like the 10mm today, the .41 Magnum in "magnum" loads was viewed as neither "feast nor fowl." Who that wants the power of a .44 Magnum is going to "settle" for the .41 Magnum? At the same time, the larger size and bulk of .41 caliber revolvers such as the model 58 failed to attract consumer interest in the "police" power level loadings.
Is the .41 Magnum a great round? Absolutely. Is it almost as good as the .44 Magnum...again, absolutely! But MOST people seem to hover around the .38 Spl +P as their recoil, size, "comfort zone."
The 10mm was introduced as essentially the .41 magnum of autopistols" and died a swift death despite a brief recognition as the FBI's chosen cartridge...because the guns were too large, and kicked a bit too much.
Just as the .41 Magnum "revived" as a field/hunting round chambered in full-framed guns, so too the 10mm has returned from the dead as the heir apparent in the autoloading world.