My experience is, don't go crazy-wide with your new bar. I used to ride a 580mm on an early '90s bike and was shocked when I bought a new bike in 2014 and it had a 690mm on it (bars are even wider now). I almost cut it down but was advised to ride it for a few weeks first. I got used to it and found that it's a great width for me. Since then, I tried newer, even wider bars like 720mm and I've found those are beyond my "strength zone" spread. That is, too far beyond what is a comfortable hands-apart width for doing a set of push-ups. In this philosophy, the bar is at, or just wider than, the width of the outside of your hands when doing push-ups. No matter where width trends go, use what is right for your body. Obviously be open to trying new things but don't be afraid of saying no to one-size-fits-all or for being uncool for bucking a trend. Bottomline, I enjoy the great control (less of a twitchy feel) and slower steering of a wider bar.