I bought this lens as a walk-around lens. It is not as fast as my 50 1.2 but is much much lighter and most important, do not draw attention. It makes my 6D looks very discrete. It is also cheap for what it delivers.
Small; light; small and light again..; Superb sharpness even wide open; Don′t draw attention at all...
STM focus wont manually work in auto mode; In manual mode still has an delay, You cant operate focus if camera is turned off or if the lens is detached, making impossible to retract the front element, It is quieter than old focus systems but is still audible