Cheap has always been, and will always be popular with some. It’s nice that tolerances are tight, but the mention in how they “play differently” in the original post is a red flag IMO.
It's not a red flag at all.... Just different. It's something to do with the surface finish... It's MUCH glossier than any other ball that I've seen. Because of the surface finish, the balls stay cleaner, for a MUCH longer duration than any other ball that I've used.
The difference in play is only slight. The balls tend to spin more and slide more. Much like a freshly polished set. Though, they play that way for a very long duration.
From my own personal testing:
We started playing with a set of Challengers on our shop table, back in May. We have yet to clean them, and they still look like they did on Day 1.
To compare differences, I decided to switch over to a freshly polished set of Centennials. I have put in about 3 hours of play, (on a Diamond), and have noticed that the balls have the typical black pocket markings (Diamond specific), and fingerprints (from racking). The Challengers showed none of that, in dozens of hours of play.
I have just ordered a set of Aramith Tournament Series balls, to practice for an upcoming tournament. I'll note my observations with those balls. From my past experience with them, they do not stay clean for very long, especially in comparison to the Dynasphere Challengers.
Think what you want, in regards to perceived value, based on the low price... These balls are not just an excellent value, but an excellent set of balls.