Group knacks are neat, but what I think will interest more people are the plot editing powers granted by teams. These abilities are ways for the players to collectively rewrite the circumstances of a scene to represent their team's behind the scenes actions.
For example, the team type Professional Freelancers are collections of stone cold professionals, the sort of team you see represented in much Shadowrun fiction and what I think a lot of players want to play, but don't. These teams attack their runs with precision and have well designed and executed plans based on meticulous legwork. This team's plot power is 1 Step Ahead of You. Spend an edge point and place the team in an advantageous position based on a secret plan detail.
In play, it might manifest like this: the team in performing an extraction of an unwilling target. They storm the target's office building, but he gets away and manages to make it to the garage, where he has a corporate limo ready to speed him out of there. The team spends an edge and invokes their power. Suddenly the driver of that limo is the team rigger, who brings the target to the team safehouse. As it turns out, they knew the target would run to that car, and their plan was to flush him out, right into their trap.
The Street Trash power is a little less flashy (I did the most work on Street Trash, because that's what my group selected; they said they had to be honest). They simply get Blind Luck. There's no good reason for teams like this to succeed as often as they do, outside of GM sympathy (that last bit added by one of my players). Yet somehow they manage to complete their jobs time and again. When this team spends edge, it can make any roll of any sort come up in their favor, barely (as in with the minimum success level).
Just like each team has its own special knack, each team also has its own plot editing power, representing its personality and flavor. I'm not done with even half the team types yet, but the idea has been met with great enthusiasm so far, even if my group hasn't had need to invoke any of it yet. Who knows, they continue to operate this well, and they might manage to trade up from Street Trash to Professional Freelancer. It could happen.
They'll probably need to stop arguing about what the team name is in front of Johnsons first though. Going back and forth over whether you're "Exploding Monkey Fists," or "Omega Sanction," kind of knocks you right out of the professional category, you know?