I have the Canon S100 (which I'm very happy with BTW) and I too was very concerned with the apparent lag in the shutter. I discovered that the lag isn't due to the shutter. It is caused by the time it takes to auto-focus. I have found that if you depress and hold the button half way, it will focus and beep when it is ready (I think the LED flashes as well). Once that happens, finish pressing the button and it will immediately snap the picture. Once you get used to taking pictures that way, it is much nicer.