1)平 (price friendly)
2) sharp, even on subject at aperture 1.8
3) Not slow autofocus system. There are two conditions: 1. Update the lens firmware to 0.3. 2. The newer your camera, the faster the autofocus. There are a lot of posts about very slow autofocus system because the lens is using old firmware and the camera is old as well.
4)Closer min. focus distance than 55mm 1.8 za
5) Equivalent 75mm focal in APSC mode. A good form factor in full frame aMor APSC mode