I owned the S1, great camera takes fantastic movei clips (if thats important to you) great in low light. Only weaknees is that it does not have an af lamp so focusing indoors can be a pain. The AA's were a god send, the flip view screen is great. Shame its only 3.mp, but it took great photos.
Not had the panny, i think i'd go for the Z20 over the Z3