I have the 28mm 1.8 and I mostly use it at wedding receptions and am pretty happy with it. I think it does well at focusing fast in low light which is a must for me. I am not satisfied with the image quality in comparison to my other L lenses. I am interested in the 24mm 1.4 but I am concerned it won't focus as fast as the 28mm. I ran into that with the 50mm 1.2 not focusing as fast as the 50mm 1.4. Anyone with both lenses?