Switching between black inks is a non starter on the 4880, however it has roll support and much much better paper handling. It all depends on your needs. You will likely not see the difference between the prints from the printers.
I upgraded from a 3800 to a 4880 when the "double" rebate was offered. The 4880 cost, IIRC, $880.00 and free shipping. If the 3800 is now about the same cost as a 4880, I would go with the 4880, IF you print exclusively on either Matte or Glossy. Switching inks on the 4880 is a PITA and costs ~$70.00 in ink.
The real plus of the 4880 besides build quality is the paper handling and the fact that the sheet paper is held in enclosed trays and the printing surfaces are more enclosed.