We just got our R7 a few weeks ago. On the depth, it's got to be mostly a deeper footwell, because the seats in the 36 inch deep R7 are deep. Any deeper and you'd need gills.
7 vs 6.. we started looking at the R5, quickly bumped up to the R6, and after some more looking, and wheeling dealing... went with the R7. Similar to g he 8 vs 7... the R6 is only 34 inches deep, and it's in the footwell. The R6 you feel a bit like you're sitting on the floor.
Can't comment much on the color other than I'm already thinking we should have done the sandstone my wife wanted. The sapphire looks beautiful, but it's like a dark car... high maintenence to keep it looking good. The dull textured finished are much more forgiving. But who wants to drive a beige car? Lol