Though it has a responsive shutter, the SD1100 IS took longer than its predecessor between shots and its flash took too long to recycle. The camera was quick to start up, taking 1 second from pressing the power button to until it captured its first JPEG. Thereafter, it took 2.1 seconds between JPEGs with the flash turned off, making it more than a half second slower than the SD1000. With the flash turned on, the camera took 3.5 seconds between shots, which is more than a second slower than its predecessor. Shutter lag measured a very impressive 0.4 second in our high-contrast test and an even more impressive 0.7 second in our low-contrast test, which mimic bright and dim shooting conditions, respectively. Continuous shooting yielded a none-too-impressive 0.8 frame per second, again a step down from the SD1000's 1.7 fps.
Image quality from the SD1100 IS is quite nice for a camera of its class. Its automatic white balance does a good, but not perfect, job of neutralizing colors under a variety of light sources. It adds a bit of warmth to incandescent-lit shots and a touch of green to fluorescent, but does a great job in natural daylight. The camera's tungsten setting did a good job of neutralizing the harsh yellow cast of our tungsten hot lights. While noise isn't completely nonexistent at ISO 80, you'll have to look quite closely to find any at this lowest sensitivity or at ISO 100, and both settings offer pleasingly sharp images with plenty of shadow detail. By ISO 200 you'll start to notice noise, especially in shadows, though there is still plenty of sharpness to the images. At ISO 400, noise still isn't over the top, and there is a surprising amount of sharpness, though I saw a noticeable roll-off in shadow detail. Things get precipitously worse at ISO 800, though you still might be able to get a decent 4x6-inch print under ideal circumstances. By ISO 1,600, images look as if they're shot during a hailstorm. I suggest staying below ISO 800 whenever possible.
Given the success of the SD1000, I was surprised that Canon let the camera's shot-to-shot time slide with the SD1100 IS. They make up for it a bit by adding optical image stabilization and keeping the impressive image quality of its predecessor. Despite my whining, the SD1100 IS is still a very nice camera, and if you're going to make a trade-off anywhere, I'd rather wait a bit longer between shots than sacrifice image quality or shutter lag. As long as you don't mind the long flash recycle time, Canon's SD1100 IS makes a great choice for a relatively inexpensive ultracompact camera. If optical image stabilization doesn't mean that much to you though, you should probably see if you can find still find the SD1000, since you can get it at a very nice discount if there are still any available.
(Shorter bars indicate better performance)
(Longer bars indicate better performance)