To sum up? If you're thinking about getting a sous vide cooker, here's who I think would benefit most from it:
1. People who tend to overcook their food. TBH, it seemed pretty impossible to overcook food with this. All of my recipes came out perfectly done. A few had to cook longer than I expected (like the egg cups and the rice pudding), but when I was patient and gave them extra time to cook, the result was great.
2. People who don't mind cooking recipes that take some time. If you're looking for an appliance that helps you cook 30-minute meals, the sous vide isn't it. But if you've got time to spare and you don't mind a longer wait, I'd highly recommend giving sous vide a try.
3. People who love the convenience of letting food cook unattended. Similar to a slow cooker, sous vide meals pretty much cook themselves — and that's a big draw. You can leave the kitchen to do other things, knowing that the sous vide is doing all the heavy lifting for dinner. But you'll also want to make sure that your kitchen is equipped to do that. I didn't have a large enough pot for some of the bigger items, so I had to check on my sous vide every few hours and refill it as the water level got low. (If you use a deep stock pot and fill it to the brim, you likely don't have to worry about evaporation and can leave the gadget alone.)
4. People who won't mind the price tag. As mentioned, sous vide devices aren't the cheapest appliance around. The version I tested was $120, but there are plenty of alternative versions you can buy for less.