Re the comments below regarding focus issues:
According to Japanese user web sites, this lens has the following problem with auto-focusing. Some users have complained to Canon. They have acknowledged this problem but claim it is a "design feature".
The spherical abberation of this lens when focused to close distances is apparently large (according to Canon, this is because this lens, unlike the 85 mm/F1.2, has no floating element). Due to this spherical abberation, the focus shifts at different aperature stops. So while autofocusing works perfectly at F1.2, the image goes out of focus when other aperature settings are used. The only way to fix this is to manually focus, WHILE stopping down using the preview button. There were speculations in these user web sites as to how this problem could be solved: either the lens design has to be changed to minimize the spherical abberation, or the lens focus algorithium has to be charged to compenstate for thsi focus shift depending on the F-setting.