Dreamer is gcode as far as I know. The gcode file is produced first then the gcode file is converted to an X3G file. Programs like S3D output both. Default extrusion multipliers for the Replicator clones is PLA .9 and ABS at 1.0. Any change more than .1 is a lot in most cases.
If S3D has a profile specificaly for that printer then it would be the good one to use.

As far as extrusion multipliers go I would run through the calibration cube exercises to figure out proper default settings. You may be getting under extrusion due to the filament not being the size that is set in the machine. It is important to measure the filament diameter over a distance and enter the average into the slicer.