What 200mm at f/2 actually gives you
200mm reaches well past what the eye picks out, compressing distance between near and far subjects.
f/2 is fast enough to keep shutter speeds up in poor light and to separate a subject from its background clearly.
Size and filters
At 1588g (3.50 lb) this is a lens you plan around — it wants a larger body to balance against, and a tripod collar or monopod for extended use. A tripod collar is included, which moves the mounting point to the lens's centre of mass rather than hanging the weight off the camera's tripod thread.
Filters are 105mm — worth checking against what you already own, since polarisers and ND filters at this size are reusable across any other lens sharing the thread.
Autofocus, stabilisation and weather sealing
Autofocus is driven by an STM motor.
There is no optical stabilisation in the lens, which matters more at this focal length than at any other: on a body without IBIS you will be holding shutter speeds high to stay sharp.
The barrel is weather-sealed, so rain and dust are a manageable risk rather than a reason to pack up.
