I feel the same as Trimmer, and real-world experience tells me that anything coming out of a 12g at close range is a serious problem for the recipient.
First of all it shreds everything it hits. Second at extreme close ranges even the escaping gas provides a serious injury, and has a near explosive effect. Lastly consider the blunt force energy dump of all that lead in a tight little cluster at extreme speeds..its like bean bag, only the beans are made of lead and there is no bag.
If you consider the question as bird vs. buck, there are a lot of arguments you can make. If you consider a 12g with birdshot vs. your pajamas and a flashlight, certainly the gun is better.
At the very least, if I had to deal with a guy as he came through the door, or the same guy after sucking up a few #7.5s, Id prefer the 'after' guy than the before guy.