I bought the S110 recently and could not be happier. I have no use for the wifi on the camera - I'm always going to copy the image to another device before sharing - and the menu options are easy enough to navigate. Plus the S110 has some touchscreen capabilities.

The slightly faster lens (f/1.8 v f/2.0) and slightly larger sensor might make the S120 compelling but I don't think they're worth the significant price premium being charged today.