And that should tell us exactly what? That usually you train your hamstrings like an idiot, but when you accidentally find an exercise which you can't cheat with, you are all fired up and amazed how good it feels? Let me tell you little secret: When you know how to train and do it always right, your body will be sore after every fucking exercise. Can you understand? It make no difference if you are training hamstrings or latissimus or whatever muscle, if you do it right, your muscle will be sore. In fact that is kind of the key for the building muscles, saying "no pain no gain" must be familiar to you in some way?
What is this bullshit? Fairly subtle changes in a movement can completely change how it hits your muscles. It's not about doing the movements correctly or incorrectly. Even on machines, where you're locked in and can't really cheat, there's differences on how the exercise hits the muscle(s). One angled leg press may hurt you knees whereas another may not, may hit you hams more or less, same with leg extensions or whatever machine.
As far as stiff leg deads, there's not even a correct way of doing them. Some stand on a block, meaning they have to round their back to get "full" range of motion. But try doing stiffs wih an arched back, with a locked knee angle, and most can't go much below knee level.
