If you haven't already read my glowing review of Snotgirl #1 then you should just do that. Don't worry, it's spoiler free. I'm not big on convention exclusives. By that I mean I don't buy them, but I get that they're fun and when you're at a con, ten bucks for a different cover really isn't a big deal when you're spending thirty on cafeteria food and another forty on bottle water. I've spent ten bucks on total bullshit at a con so I'm not opposed to it. I just don't do it anymore.
That said... I would buy the fuck out of this cover. Bring a bag and board if you're going to pick it up.