I noticed Henderson had 'time' quite early in his Sunderland career. All good midfielder have it, Xhaka and Le Fee for example. Hopefully Sadiki will continue to grow too.
Colback and Meyler were work horses, no real class.
How do you have time? You find space to receive the ball, your first touch is immaculate not allowing anyone to think they can pinch the ball. Then you have options, to play it quickly, to hold it, to carry the ball, to go left or right. The defender can't easily close you down because he has no idea what you are going to do.
Colback's first touch was OK, but he was very left footed closing down his options. He never had time like Henderson.
Le Fee and Sadiki are a bit different. They always keep the ball moving to avoid challenges, to give themselves time to pick a pass. Xhaka just glides through the game not unlike Henderson but it is easier to do it playing deeper where the pitch is less congested.