The M4 Sherman was a good, solid, general purpose, workhorse tank.
It had a fast turning, 3 man turret. A versatile 3 inch gun. Sloped frontal armor. And a reliable transmission.
It was a medium tank, designed for infantry support.
It could hold its own against any medium tank ever made... and it outclassed a few.
Like all tanks, the M4 had a few shortcomings... but it was a generaly well rounded tank.