The 7x57, along with the 6.5x55, are cartridges that by their existence prove beyond doubt that newer is not necessarily better. It's almost as if the designer knew not only what he was doing at the time, but what wonderful propellants and projectiles would be available beyond his lifetime. Smooth feeding, easy on brass and shoulders, bore diameter that is sufficiently supported by your basic soft point bullet, plus the vicarious link to history thru the use of a 100+ yr old round. It is a proven standard, an often copied blueprint, a routine success. Good grief, I believe I just defined "fun".
