ZDNet just posted a review of this camera. Like most ZDNet reviews it lacks the details that a camera centric site would have. In general they like the camera and recommend it, but they do highlight one notable issue: relatively high shutter lag (0.5s to 1.2s) and recycle time (2s). ZDNet's same tests ran on the SD850Is found a shutter lag of 05.s to 0.7s, and a recycle time of 1.7s.
Note that all of these times are at full resolution. Personally, I prefer to shoot at less than full size to get higher speed and less disk consumption.