I am currently awaiting a shipment of fresh current paper from Red River.
With all my new Profiles from this table http://www.precisioncolors.com/PC42ICC.html , all the Canon papers look essentially the same colorwise. This is what profiles is supposed to accomplish and it does. The only intrinsic difference is the tonality of the highlight (paper white bias) and its effect on the tonality on B&W. There are very small detail performance differences in the dark shadows, but you need to go hunting to find them. I suspect the mixture of the ink plays a large part. If you need consistent output, then theoretically until all the inks become pure, each refill will require a new profile especially if you're picky about colors. To come to a consistent point, you need to flush to attain consistency.