I have a Canon G6 (7.1mp) and a Canon 20D (8.2 mp).
1. There is tremendous difference between jpg and RAW in both cameras. Certainly the biggest difference is the total control one has with RAW as apposed to the camera's internal "developing" process but it doesn't end there. In any event, the differences are the same in both cameras.
2. I find no difference between the processing of the RAW images from the two cameras. The technical aspects (the settings) of capturing an image is the same with both cameras -- the only difference being the fixed vs changable lens.
I might add (at the risk of a "sour grapes" impression) that I, too, would be the proud owner of a G7 if only for this jpg/RAW issue. In fact, I had the funds set aside specifically for that purpose. (I had gone from a G4 to the G6.) I suspect that the funds will be waiting for the next generation unless some other brand of P & S, with those specifications, captures my attention. In the meantime, there is nothing that I don't like about the G6. Of course, I can say the same about the 20D although the 5D has my attention.
Ron