Of the three, I would buy the G-10 for its manual controls. It has an old fashioned dial for ISO setting, and another dial for exposure compensation. Easy and fast. These are two of the most often changed settings, and most compact cameras bury them in menus. The G10 also has an optical viewfinder. It's not perfect, but it's not too bad. (I own the G-7, and its optical finder is pretty bad.) Finally, it's a pretty quick camera to use. It just feels "snappy."

The only downside, besides the size and weight, is the small sensor. It's good up to ISO 400, not so good after that. But the image stabilized lens makes it possible to shoot fairly long shutter speeds and maintain sharpness. (This doesn't help when the subject is moving, of course.) The zoom range from 28mm-135mm (equivalent) is fine for general use.

I've been generally happy with my G-7 as a backpacking camera, and I think the G-10 would be a great choice.