Canon SD780 IS / IXUS 100 IS vs Panasonic Lumix DMC-FS15 – Alexandra Savvides had this to say about the high ISO performance of the SD780 IS / IXUS 100 IS in comparison with that on the Panasonic FS15:
Noise was relatively well controlled thanks to the Digic 4 image processor, and on par with what we've seen from the other Canon compacts from this 2009 range. It performed better in controlling noise than the recently tested Panasonic Lumix DMC-FS15.