This reply probably won't be of interest to you (but might be for someone else):
I don't do street photography, but back in January I obtained a GR (the IIIx) for my 'always carry' camera. For me the Large JPEG files are very good and usually close to what I want, so I don't bother saving the huge raw files. In 'Picture Control' I've been mostly using either the 'Positive Film' style or the 'HDR' style, depending on the scene. The Large JPEGs are then usually edited to my taste, using PaintShop Pro, for screen viewing and/or for some prints up to A3+ in size (the largest my printer will do).