I switched from 50-34 to 52-36 on my road bike a little over a year ago. I did it because (1) it gave me more top-end speed before spinning out, and (2) it didn't penalize me much at the low end. I live near a lot of mountain climbs. At the same time I went to 52-36, I also went to 11-34T in the back. With that switch, I didn't lose anything to speak of compared to a 50-34F/11-32R setup.