Bent shaft paddles are supposed to be easier on your wrists and elbows minimizing joint problems by maintaining a more neutral position.
Straight shafted paddles vs. bent shafted paddles is strictly a matter of personal preference! If you have joint problems you will find that tthe bent shaft paddles are more comfortable. As a whitewater paddler I have used both but prefer the bent shaft. I can do all the strokes - the notion that the bent shaft limits or eliminates certain strokes is ridiculous! My suggestion is that you find a paddle you are comfortable with and go with it...each person is different!