Epson R3000 versus Canon Pro-1 (Review)

This is very interesting:

"Pigment Agitation. With the ink stored in an immobile tank, how does the R3000 agitate the pigment so it doesn't all settle at the bottom of the tank? You can actually hear it agitate the ink using a pressurization system borrowed from the Epson 3800. It sounds a bit like a vacuum cleaner every now and then as the pigments are stirred up in the tank using fluid pressure."