i-Contrast: Canon's new exposure-boosting technology seems to lack some subtlety, overbrightening midtones a bit. The shot with i-Contrast enabled (left) also looked a tiny bit softer than without (right). But it's fine if you're shooting in Auto and just care about getting decent exposures.
Noise: Although the G10's noise numbers are slightly higher across the board than the G9's, visually the results look better. They're definitely usable up to ISO 400, but detail starts to degrade at ISO 800 and pretty much disappears by ISO 1600.
Fringing: Overall, there's very little fringing on the G10's photos. Aside from the very high-contrast edges where you expect to see it, there tends to be a bit on the left side caused by the lens distortion.