Can't respond directly to the 210, or even quality control in relation to the older models, but...my MB212-ii, aside from the great tone and portability, has been BULLETPROOF. I can only assume that the quality on the second-gen 210 is equal.
Of course, with any mass-produced product, there will be lemons. But word is that GK customer service (I've never personally had to use them) is excellent.
New York Bassists #55 / Classic Vibe #166 / Fretless Club #862 / G-K Club #976
New album! thedrunkardswife.bandcamp.com