I just received the Nikon S9100 as a christmas present. I had been comparing it to the Sony and Canon equivalents but the longer zoom on the Nikon was a tipping point. All in all I am not disappointed at all.
The camera works very well, as I expected. There are a few small glitches - it has a hard time autofocusing in higher tele values and the photos at longer zoom values tend to have a little softness towards the edges. These were the only drawbacks I could find. The positive points more than compensate for these small flaws - lots of programs to choose from, auto mode is more than adequate for 95% of the situations. The camera responds very fast (turning on/off, changing programs,...). I was particularly impressed with the quality of the photos in low light. I rarely pop up the flash.
All in all, this camera is a great substitute for my aging Canon Ixus S800.