i find injection much faster, as you can fill multiple cavities at the same time. now as far as economical small bench top machines go, there is jacobs (looks ok, but limited to 1 colour, a 1 quart holding capacity and is held in a heated container) and Bears bench top, which cost significantly more than jacobs, but it is capable of 2 colour laminates, it looks to hold at least 3 gal in each "hopper" (2 hoppers) and uses 2 1.2lb heat exchangers to heat the plastic just before it hits the nozzle.
Now you could contact Zorn Molds as well to see what they have to offer (i am waiting to hear from them) but get ready for their costs as these guys dont screw around (they supply some big companies injection equipment)