I am confident on this. I keep notes in a custom xls every time I change a cartridge or a maintenance tank. Of course I assume that the Accounting Manager software gives reliable data and that the ink in the maintenance tank stays always in liquid form! If it's not then the consumption is worse 
Just to be clear. I trust your observations. I have seen worse waste than this on the Pro-1000. But even a 1:1 I find absurd.
There are two interesting post here from user Czornyj which reports a very low ink wastage 6.5% on a PRO-4000. Also this post is the first reference I saw on the PF-10 printhead lifetime, 8-10lt of ink on average:
http://forum.luminous-landscape.com/index.php?topic=120755.0
Yes, this is why I find the 1:1 ratio really absurd on the Pro-1000. This observation on the Pro-4000 seem more normal, but likely also with more usage. But you have still used your Pro-1000 fairly regularly, and I still wonder if wasting this much ink compared to what lands on paper is really expected behaviour, or the Pro-1000 simply has some design fault, be it firmware or hardware.
It does share the same inkset and head, and although other things likely differ somewhat, keeping the same head type and ink ready for action, I would except takes roughly the same amount of maintenance - not suddenly exploding on the smallest model. Even if you printed more (volume and higher frequency), there is a _long_ way down to hit around the same maintenance usage as the reported Pro-4000. Just wandering... Canon, are you listening? Could your thorough data collection be submitted to Canon for a comment?
If it doesn't change, a Pro-2000 might be a better buy (assuming it behaves as a Pro-4000), if it can fit in - unless someone reports the same heavy maintenance here as seen on the Pro-1000.