2 is nice. 3 is better. And let me now explain why. With dual filaments we have 2 hotends that are linked and the one not being used oozes all over the print. Or we have one hotend with PTFE tubing that is Y'd together and we have to figure out ramming sequences and travel distances. Or we have an idex and have to calibrate so the seperate carriages go to the same place for printing. But with a 3 in 1 out mixing hotend all 3 filaments are just right there sitting in the nozzle ready to go. You select the color you want to use and start feeding it. There is no toolchange required. Sure there is more work to be done to achieve mixing and understanding ratios and what colors they make, but to just use it for 1, 2, or 3 color/filament printing it is the simplest way of getting the job done. Because no filament ever needs to be retracted before another filament is fed in. There are only a few 3 in 1 mixing hotends out today. One that is old and has been around for years now. The Damond Hotend. There is a new design of a 3 in 1 mixing hotend out now. It is made by Geeetech and here is their largest build volume printer with the 3 in 1 mixing hotend. For your consideration check out this printer that I myself would love to own: Geeetech A30T 3-in-1-out auto leveling mix color 3d printer [800-001-0613] - $479.20 : geeetech 3d printers onlinestore, one-stop shop for 3d printers,3d printer accessories,3d printer parts