Cameras the size of the SD1000 are considered to be Ultra Compact Cameras.

I see no difference in the photos from the SD1000 and the SD1100IS.
The Image Stabilization of the SD1100IS is an advantage, because cameras of this size/weight are notoriously difficult to hold steady.

To my eyes, both camera could benefit from having a tad more image sharpening. They could have done this in the firmware of the camera.
But since they didn't, you could use any photo manipulation software to add a bit of sharpening if you think it needs it. I tried Irfanview free software on some sample pictures from both cameras and it added that extra sharpness that I like.

You might also look at the Sony W120. It has image stabilization too.
I thought the sample photos from the W120 were better than the images from the W130. (The W130 has one more megapixel but does not benefit from it).

The Sony cameras have a bit more optical zoom (4X).