The Food Lab's Complete Guide to Sous-Vide Steak (J. Kenji López-Alt, Serious Eats)
"As you can see, the steak cooked for just one hour stretches and pulls when you tear it. This gives the steak a pleasant amount of chew. It's still tender, but it tastes like a steak. By the time we hit four hours, that chew has been reduced a bit. Connective tissue has broken down and individual muscle fibrils split apart easily instead of sticking together, though a four-hour steak is still pretty decent."[more inside]
Serious Eat's The Food Lab cooks The Perfect Rack Of Lamb. "You don't have a $450 low-temperature water oven"? Good thing it isn't necessary...