J Russell is the better QB of the two right now, and has better upside. Also as far as the offense goes he is much more accurate than Quinn so he fits our offense better in that sense, he also throws the deep ball better which also fits our offense. He also can handle the rush better than Quinn, quicker release and better feel of the pocket (although he's not a scrambler) and that fits our crappy offensive line better than Quinn.
The only thing Quinn seems to have over Russell is his desire to be great, which MAY translate over onto knowing more about formations and defenses. I'm not going to slight Russell in this regard for irrelevant preconceptions about his race, attitude, the way he speaks etc etc. However, it is unknown how he will approach the game and its reasonable to say that Quinn has shown how dedicated he is.