We bought a sous vide cooker. We only got it yesterday and all I've cooked in it was an egg, but already I've got some thoughts.
The appeal of sous vide cooking is easy precision. You dial in a specific temperature to a water bath and let your eggs, or meat, or veggies hang out for an hour or two at that temperature and you get perfection. The variance in temperatures is amazing. Eggs go from runny (but pasteurized) to hard between 58°C and 70°C. Beef goes from rare to medium between 51°C and 60°C. Traditional cooking on a hot stove requires the cook control the final temperature with time. Sous vide lets the cook just set an exact temperature and forget it; there's no risk of overcooking. For someone like me with no kitchen skills, that's very appealing. But so many caveats.
First, sous vide cooking is slow. A hamburger takes 2 hours. A big chunk of meat can take 2 days. It cooks entirely unattended but you do have to plan ahead. A related problem is you can only cook to one temperature; no cooking both your meat and your veggies in the same bath. And when the sous vide step is complete you're not finished. Meat still has to be browned or seared, and seasoned, and finished. And while an egg yolk may come out creamy at 63°C if you want a firm white you need a final hot boiling step (carefully timed).
The other issue is equipment. The Sous Vide Supreme we bought is pretty well built, but at $450 it's an awfully expensive gadget. It takes up a lot of space. And you really want a vacuum bag sealer to go with it, another gadget. I fear if we store the kit away next to the mixer, the food processor, and the blender we'll never use them.
I'm optimistic the sous vide cooker will get some good use in the house. It's simple enough even I might be able to cook well with it. But it's got some drawbacks.