this lens in the B&H online catalog had initially shown a different lens design than the 14mm Bower (samyang et. al.) I could not get a good answer on line from Ask B&H but in visiting the store and looking at the actual specifications it is the same as the standard Samyang lens 14 elements and 12 groups not 16/13 as initially posted.
What I like about this lens is that there is very little CA noticable in the shots, even wide open. It covers a full frame viewfinder with no visible vignetting (I will have shots next week from my PZ-1 as well.
You can see the distortion at the top and bottom of the frame, but this is easily corrected if you want to remove it