The quick change is definitely zinc alloy.Used to be a Weishi. Dorco Prime switched to the Baili within the last year. What do you know about who's maufacturing these things? Do you think there is really an all brass version? What do you think about Viking's claim that it's their design?
As to the quality - you're right, Baili's doing a nice job on their recent razors' chroming and stamping. You probably know this, but one way to tell, especially on TTO's, is to look at the base plate from a side view - particularly the "L" shaped 90 degree bend that makes the safety bar. On most all Weishis (on Parker's too), the bend will not be a uniform 90 degrees on both sides - one side is always off. The old Gillettes and the Baili are pretty even on both sides.
I would put it up against any modern day tto for quality, consistency and plating.
Only benefit of brass is if you think the plating will wear. Then you might want to re-plate, but you are not going to spend $30-50 replating a sub $10 razor, at least I'm not.