I have and use this lens (the non-zoom-through variety), and am quite enthusiastic about it.(posted 9026 days ago)The adapter locks on securely and easily. The image is not noticeably degraded (although, even without the adaptor, the Canon 16X lens goes a bit soft when all the way wide). The unit is compact and (relatively) affordable.
To me, the adaptor makes much more economic sense than the Canon wide angle zoom.
Really, nothing bad to say about it.
I have and would recommend the collapsable rubber lens shade made by century, which helps control flaring.
BW