In USA the Digiwave motors are sold as SG2100 and newer model SG6000. The SG2100 is also branded Motek by some vendors.
In the picture from Rolfw post above you can see the PCB is marked SG2100.
There were three different versions of this motor here the 'One button" motor was considered the best. Some do diseqc 1.2 only and some do USALS. However, they likely don't have license from Stab to use USALS.
Plastic gear or metal gear will run smooth and quiet if "Backlash" is adjusted properly.
http://www.satellites.co.uk/satelli...280-backlash-adjustment-moteck-sg-2100-a.html has instructions on adjusting backlash.
From what I've seen, the original SG2100 was a Tiawan product. China took over production at lower cost, greater profitability for vendors. Quality control was terrible at first. Now with SG6000 better quality and better design. With SG6000 they copied the Stab mounting bracket and solved the bracket deformation problem with the SG2100.
The DG series has the metal gear but does not seem to work any better for 1.2 meter dish.