I'm guessing it's going to be the Zeiss however I won't know until I shoot all 48 exposures (2 x 24ea.).
While the $'s spent were pretty close, the Brightin Star is new out of China for the Leica M-mount (I'm shooting it on the M3). The Zeiss is an older lens for the Contax G-series but I suspect that the Zeiss behavior will live up to its legend.
Bastiank @ Phillip Reeve had this to say about the Brightin Star and this about the G-mount Biogon. I suspect his reviews will be A LOT more thorough than my simple comparisons.
I was thinking last night that I'd load up the M3 with another roll of UltraMax and take it out with the Brightin Star and the gx9 to get a series of similar digital/film shot for eventual inclusion in a future THREE TWENTY-EIGHTS article.
I suspect the Brightin Star is a gimmick lens. I'm bummed that my film got trashed, I really wanted to see it against the Zeiss Biogon and the 14mm Panasonic.