As far as I know teraset is more of a reseller kind of. They buy the duckys from somewhere (I don't want to say where, scared of being wrong

) ), then sell them to other people. As far as being trustworthy, yes they are

I've never heard anything bad 'bout them, and the customer support was awesome when I took contact.
Bear in mind I'm very new to this whole mechanical keyboard thing, so there might quite a bit I don't know about different sellers etc.!