In all seriousness, there is a reason that one of the main mottos of the game has been "Shoot straight, conserve ammo, and never cut a deal with a dragon." Not sure if it showed up in 4E, but it's been the bit of knowledge every runner should know since I was knee-high to a grasshopper. And the reason for that is because the dragon WILL win. And usually come out smelling like roses. In Shadowrun, they are the deus ex machina. Even hatchlings come out dangerous as hell, and they only get worse from there.
Best bet for runners, is to avoid dragons. Best bet for a GM, is to wait for a couple of months of street level runs, and then have the dragon announce that they have been working for him through intermediaries for a while now, and their ability to surprise him is greatly reduced. You have to get up awfully early to surprise a dragon. Like, back in the Fourth World early...