You ask how does the Canon G-9 compare? Then, I must ask: Compare to what? Logically, you cannot, or should not compare it to an ultrazoom camera or a DSLR camera. However, when compared to its very able 10mp forerunner, the Canon G-7, the G-9, at 12mp and a handful of new features does represent a significant step forward. At least that is how Popular Photography magizine, here in the USA, has characterized, the new Canon G-7.
Here are a Canon G-7 photo sample and a canon G-9 photo sample. That might offer a platform for some comparison.
Here is the Canon G-7 sample photo: