Everyone above is correct, no riser is right or wrong generally speaking but when it comes to the individual there is a huge difference in just a few inches. So don't think pullback is right or straight is right think about what is wrong with your riding position and what adjustments you may want to correct it. For me my bars were too far forward and my wrist position was wrong so I put slightly taller risers on with a pull back angle to bring the bars closer to me and I changed my type of bars to make the distance my arms are apart and wrist position better.

I learned all I need to know about life by killing smart people and eating their brains.
Eat right ,Exercise ,Stay fit, Die Anyway!