To expand a little on zor17â€™s post, I too believe that paper handling capability is the biggest difference that separates the 1800 from the 1400. On Epson Matte Heavyweight (or whatever they are calling it today) or Ilford Classic series papers, my 1400 produces color prints that, I believe, are as good as it gets. And, if you stick to the papers I just mentioned, the permanence projections are quite good. The problem is that virtually every other paper available is â€œoptimizedâ€ for pigment inks, which has a detrimental effect on dye inks. And, if you want to try thicker media like fine art paper or canvas, the 1400 wonâ€™t work at all.
Also think about icc profiles. Makers of fine art and canvas will almost always have a profile for an Epson 2400, less frequently for an 1800, and almost never for a 1400.
Finally, donâ€™t let the purchase price of the printer unduly influence your decision. Even with a moderate amount of printing, consumables will easily exceed even the price of a 2400 before you know it.
If I had it to do over again, I would go with the 1800.