I have two of these motors from this vender http://cgi.ebay.ca/ws/eBayISAPI.dll?ViewItemVersion&item=232236292051&view=all&tid=1450117362013 appears to be the same thing.
Mine has all metal gears in it and appears to be well made! I’m still waiting for the shield to come from Maslow and the sprockets to come from China. I will be building a lighter sled and using a Bosch Colt router that I have modified for a er11 collet. I have some experience with CNC machines, I built conventional CNC routers and I converted my metal lathe/ milling machine combo to CNC control but I have never worked with servo motors and encoders before!