I'm really unhappy with this Gizmodo review, but they've got the steak part nailed. It's exactly like they say: you take a steak, bag it (I season it and throw some butter in), and then set the temperature for 130. Wait one hour or 48 hours or any time in between: you will get a uniformly perfect steak.
Do this two or three times and you'll stop poking or probing the final product. It simply is 130f, inside and out, when you remove it from the bag. Checking the temperature is essentially second-guessing a very very accurate electronic thermometer.
The quality of that finished product will be higher than anything you can accompish on cast iron, because cast iron doesn't heat meat uniformly. To get a rare center on cast iron, you have to accept a medium-well band of meat on the outside of the steak. Skill and technique dictate how wide that band is, but it's there regardless.
What you lose in SV is the seared crust. So, of course, after you cook your steak SV, you sear the outside --- for seconds, not minutes, on each side --- and then plate.
There are three major benefits of SV for steaks.
First, no matter who you are, SV is the one way you can set up a couple steaks in the morning before you leave for work and come home with a perfectly cooked steak waiting. It's this benefit that makes me think SV is the future for the American kitchen.
Second, if you're a typical home cook, SV kills the margin of error. Unless you type the wrong temperature in, you're getting a perfectly cooked steak no matter what you do.
Third, if you're a pro chef, SV frees you from having to be an extremely expensive meat thermometer. Electronics are better at watching temperatures than people are. Chefs are freed from the drudgework of monitoring cooking, and can spend that time innovating or refining actual dishes.