Straight arm technique
Pros - more speed/spin/ deception in ball placement, ( looks cooler hahaha ).
Cons - Longer recovery time period, requires better footwork for consistent straight arm shots, poses greater shoulder injury chances.
Bent arm technique
Pros - Easier/ more consistent, Can be played to a degree even if the ball is in your crossover point pocket, faster recovery time.
Cons - less speed/spin hence easier to counter attack/ deal with for opponent.