After testing it more in good light outside I can say , that yes, it's slower than the kit lens at autofocus. Sometimes it seeks for a long time when you are on center focusing and is not acquiring focus at all (fortunately it doesn't happen to often), but this almost never happens with the 18-55.
And to my knowledge, it doesn't matter what aperture are you at, and what ISO or any other setting, the autofocus should be independent of that and only be influenced by the light outside and the contrast of the subject.
But besides that, I'm extremely happy of the image quality, color contrast and bokeh are beautiful, and also the focus is spot on, I was affraid I will have front/back focus issues, but is not the case. Even at 1.4 I have some pictures that are sharp (to my surprise
) You can see the image bellow (taken in jpg, cropped, resized 50%).
Click after the image is open to expand on the screen otherwise it's resized by imageshack I guess.