I had the ZS3, but I was just too used to carrying around a ultra compact that I sent it back and got the ZS1, which I really like. Its much smaller (and fits in my old Casio EX-V7 case). No doubt the video is not quite as sharp as the ZS3 but still decent.
I'll shoot that bee's nest shot with the ZS1 saturday so the full zoom qualities can be directly compared (its up in a tree).