We were lucky enough to speak to pilots who have flown jets equipped with thrust vectoring nozzles (TVC) to get their opinion of the J-10B flight demonstration at Zhuhai airshow.
It was clear that the nozzle did vector downwards but only for a small degree. The minute deflection was enough to generate the lift necessary to keep the nose up during the pass. The angle of attack was between 20-30°. Even during the cobra maneuver, not much deflection of the nozzle is necessary to execute the classic move.
As this is a single engine aircraft, the benefits of the TVC is limited to the lateral axis unless the engine can produce high thrust to weight ratio to contribute to the other two axis.