Sous Vide as stated several times already in this thread, cooks the meat at low temperature for an extended period. Does that sound like another cooking method that I'm pretty sure alot of you guys probably already do? Like maybe smokin? And why do we smoke a pork butt low and slow for 12 hours? Besides the taste, it breaks down the connective tissues in the meat and makes it so tender you can pull it apart with a fork. You can get similar results with your Sous Vide, although with a steak you wouldn't do it to the same extent. But you can take a less expensive cut of a steak like maybe a sirloin and elevate it to the tenderness of a filet mignon and few would know the difference when done right.
But if you do it too long your meats can take on a sort of odd texture that some people that are texture based eaters will not like.
I have Sous Vide prime ribs, pork butts, chuck steaks, pork chops and a bunch of other stuff and almost everything turned out really good.
Do you like soft boiled eggs? Try throwing a couple eggs in the Sous Vide at about 147 - 149 degrees. The white will be cooked and the yolk will be creamy and delicious.