Thomas- It's a nifty little gadget...It's calibrated to specific papers and developers, allows 1/10 grade changes instead of 1/2 grade, compensates for dry-down,and allows you to program multiple burns at different times and contrasts. I can get a perfectly acceptable print on the first sheet of paper, although I will often change it slightly to change the emotional impact, or emphasize the subject matter.
I can make a print on Ilford MGWT fiber, decide I'd rather have it on Forte, switch the paper selector to Polywarmtone fiber, and it makes the necessary time/contrast changes. I don't think it allows you to do anything you couldn't do with regular split grade technique, but you'd have to calibrate your filters/colorhead for the separate exposures necessary to achieve the 1/10 grade changes.