I own a G5 and have been very pleased with it. It has several advanced features: selectable ISO ratings of 50 to 800, a number of white balance settings, exposure value settings, ten or so exposure modes (i.e. shutter and aperature priority, full auto, program, manual, etc.), accepts an external flash, the ability to shoot RAW, solid optics for a point and shoot, exposure lock, and a fold out a LCD screen that is actually useful at times–lots to like. However, it is slow to startup, has an annoying lag time between shots, especially if it is recording larger files, and it is a bit big, even for a bellowed front shirt pocket. But, it is still much smaller than a DSLR and the almost DSLRs.
I owned a G2 before purchasing the G5 and would highly recommend both. I would think that the G7 would be just as good, if not better.
Bryan