Bob, all printers leave ink in the cartridges. It seems now someone with a 3800 decided to open a cartridge. I have a Canon iPF5000, the ink left varies between 5ml and 12ml. We all hope that the manufactures add extra ink knowing that some will be left.
HP does not have a 17" printer at this time so your main options are the Epson 3800 and 4880 and the Canon iPF5100.
All will produce nice prints. Epsons can do borderless on sheets, Canon will not. Epson 3800 no rolls, 4880 and iPF5100 use rolls. Ink costs per ml is less with the 4880 and iPF5100, the 4880 will be less if using the 220m carts.
The 3800 is very small-only 2" wider than most 13" printers. The iPF5100 is huge. You think you do not need rolls but they help sometimes. You can get 16" rolls and have 16x20 prints made with no trimming needed. The iPF's allow very long prints if doing pano's. Not sure on the 4880 but the 3800 is limited in length.
The iPF has both blacks and does not waste any switching papers. The 3800 and 4880 both use ink switching between matte and glossy.
You probably used a lot of glossy with the i9900. Once you use pigment inks you might start heading towards matte papers-they help with gloss differential. I hear the iPF5100 is much better with gloss differential and bronzing than the iPF5000, not sure about the 3800 and 4880.
The newer epsons seem to be much better keeping nozzles clean.
My iPF 5000 was low on ink and I needed another set so for not much more I bought a 5100. I have not installed it yet. But, if Epson had the next generation of the 4880 running both blacks I would have concidered it for the borderless printing on sheets.
I do not print as much as I should owning a big printer. I am sure I use much more ink in cleanings than printing but I would expect the same to be with the Epson.
If size is an issue the 3800 is really the only option. If size does not matter the 4880 or iPF5100 might be a good choice.
Oh, the smallest sheets the 5100 can print on is 8x10 and I also think the 4880 but the 3800 can print 4x6.
Anyways, I hope some of the information helps. I would not worry about what you read on ink left in cartridges since all printers leave ink in the carts. Do not let that be the reason to cross one off your list.
Tony