I did some searching around and couldn't find any reference to this subject. I just moved from an Airwolf 3D printer running Repetier Host and Slic3r. So when I started using my new UM2 extended and Cura I noticed a serious uptick in print times. If I use the same settings on Cura and Slic3r, I see a 3 - 5 X print time increase in Cura. I have gone over the settings several times and I cannot figure out why this significant difference. Except for the filament diameter difference of 0.4mm vs. 0.5mm that should only account for 25% difference, not 400%.
For all intents and purposes the machines operate identically.
I do know that Slic3r super-fills the part by over extruding material during infill. This speed things up considerably. Perhaps because I primarily use 100% infill this would account for it. And in that case, would using Slic3r on UM2 speed it up also?
I initially tried setting up Repetier to create GCode for the UM2 but it is not actually extruding material and seems to over retract so the filament eventually sucks up into the Bowden tube. I can't seem to find anyone with a clear setup for UM2 on another slicer so I feel like I am trapped with a slow Cura solutions.
I really love the UM2 otherwise. The hardware is amazing! I just hope I can get the print times down to something more manageable.