Quite good lens overall (and the camera too).
BTW I have heard that E-P1 has special software/firmware to correct known deficiencies of known lenses. At the moment it is apparently only for M.ZD 17mm and 14-42mm. Now question is: would Olympus cameras/software compensate for Panasonic lenses and vise versa? Is there any interoperability agreement on that between 4:3 members?