As a side observation, you've chosen to format your post very strangely. It was a little difficult to parse out the text.
Two of the deciding factors for me are:
1. Socially insecure White is by necessity going to be somewhat similar to early Jade from Ignition,
and 2., I just think that the journey of the bitchy Black to be less of a bitch is going to be more interesting as well as amusing. ("Oh god why did I just say that, I'm an idiot.")
Fundamentally, most stories are about overcoming challenges, quests in particular, and the bigger the challenges, the more intersting those stories tend to be. People that are voting White because they think it'll be easier, imo, are missing the point.
If it's true that choosing Black will make our mission more difficult (and I'm not convinced that's true; For starters, White is about order and the greater good. They're just as likely to sell you out if it's for the greater good, they're just as likely to alienate people with dogma and controlling behaviour), then that is not a bad thing.
And as others have pointed out, Black and White are not about Good and Evil. None of the colors are. Every color is equally capable of being the hero or the villain.
The first two are fair. Fortunately, I dropped Ignition along with everything else when I took a long sabbatical from SV and have been too lazy to read back through the surely-very-long backlog (also tbh Jade just failed to grab me as a character the first time around for some reason, despite that I normally have a soft spot for the socially awkward and traumatized), so I'm not burnt out on shy characters. I don't really see the Bitchy Black being particularly amusing because the entire time I'll know it's not really about becoming nicer; it's about becoming more outwardly polite in the pursuit of a goal, and learning that kind of deceptiveness just removes part of the appeal for me (which is a character who is admirably upfront about her nature).
As for stories being about overcoming challenges: that's true for stories, in which you're only along for the ride, but this is a quest, an interactive medium, which gives it much more in common with games. Games that are too difficult invite frustration and hinder engagement. I'd vote for the more difficult option if we didn't have enough difficulty coming out of the premise of scheming against an immortal alien hivemind to save the world from Kriemhild Gretchen (which, let me remind you, our goal is
not Wapurgisnacht, it's
Kriemhild Gretchen). You could argue that someone with an entirely pragmatic point of view might find that easier, and (...) maybe. I could see that argument. It really depends on how cynical you are about the magical girls we'll meet and what you really think is acceptable when it comes to recruiting impressionable young girls to our cause.
(As for White being just as likely to sell you out and alienate people-- yes, certainly, but I don't see it in the White we've been presented with. I'm not working off of stereotypes and generalizations when I make these judgements of Black; I'm working off of what I'm seeing in her write-up. Although it's
possible that Black (or White) could defy my assessment-- and let's be honest: we all know SV is going to defang her; SV as a collective (like most people) does not know when to be ruthless and when not to be ruthless-- it would remove one of the greatest benefits of being a ruthlessly pragmatic Black, which is
actually being ruthlessly pragmatic.)
I'm seeing "she is Tsundere" here.
This implies that there is a sweet side being hidden by the rudeness and cruelty. I'm not seeing that. I'm seeing a strong belief in the goal of saving the world, an admirable level of honesty toward who she is and what she's willing to do for that goal, and a great deal of ambition founded on selfishness, but I'm not seeing a sweet side. At her best, Black strikes me as a shark-- predatory, efficient, and brutal. That makes for an interesting character, and one I might be far more interested in than White in another context, but not someone with a sweet side to be revealed.