Another reason for using the 38xx series as opposed to the 48xx or bigger is the cost of the black ink change from photo to matte. The 3800 is a couple of bucks, all of the others are big $$$ since they flush the system. At least one site quotes the change costing $75USD on a 4800. I think it's lower on the 4880 as they now use a "conversion kit" but it takes 10-15 minutes and still uses a lot of ink. It doesn't take too many changes to pay for a RIP on the 38xx. And, if you want to go longer than 90 inches on the 48xx, you'll need a RIP anyway. The Epson driver is limited to 90 inches.

With Qimage, you can print 590 inches long with a 48xx Epson. No RIP needed.

That is because the 3880 has no facility for roll paper and therefore no banner mode. Qimage requires Banner mode to be set in the driver.
Qimage does not "override" the driver as such but uses it's own Poster mode where a "poster" is made of 1 column and 'x' pages. Each page has to be of a size less than the driver length limit and each page gets printed on the roll as one complete seamless print image, neat!  I think my explanation is correct. Fred will put us right if not 
Terry.

Fred et al

The 3800 (and the 3880) has 4 black cartridges installed - Matte Black, Photo Black, Light Black, and Light Light Black. Only 3 are ever used at one time, the 2 light blacks and either either matte or photo depending on the paper type (automatically selected). Switching from one to the other does waste some ink - from memory it costs around £2.00 to change from photo to matte and around £1.00 to change back (or perhaps vice versa). Unlike the R1800, if you don't use matte black then no matte ink is lost when the printer cleans itself.

Brian

Fred
You don't physically change them, its done by the software like the 1800. The difference with the 3800 is that it replaces the ink in the supply tube (which you don't have in the 1800) when you change, which is where the wasted ink comes in. Sorry if I misled you.

Brian

While the 3800 has both Matte and Photo black carts installed at the same time, they both share the same printhead.  As a result, a certain amount of black ink is used to flush the supply lines when switching between the two.  This is described in Eric Chan's excellent 3800 FAQ:

http://people.csail.mit.edu/ericchan/dp/Epson3800/faq.html

Seth,
I could have suggested the R1800 too with a roll paper feed, but I think the 3800 has a great deal of good features, except for the roll paper capability.
It is a lot more printer than my 1800.
Give your 2400 a fresh ink cartridge from me and tell it that I didn't mean to insult it.   
Fred

I have been looking at the 3880 for some time but I do like to do panos. After a lot of research I have been seriously looking at Canon ipf5100 and it looks like a really good printer, although a little on the large size. It does roll, front and top feed. Lots of good paper sizes. Price is around 1450 us dollars. Does anyone have an opinion??
 
Probably  should be a different subject, but is there anywhere to research what kind of papers do certain types of photos the best? ie, Black & White look good on Ilford (Hanamuhle, Epson, etc) Color landscape on luster, semi- gloss, or matte? There just seem to be so many choices a guy could go broke just getting samples and profiles to do any of it some justice. Any ideas?

Mike