If you just want a helmet the Citi is a good choice. If you ride year round the accessories on the Metro are very nice. I got one last year and really like the rain shield and helmet liner with ear flaps. Due to my large head wearing a hat under a regular helmet is very difficult. The Metro allowed me to get away with a liner down to 10F. The mirror is not the greatest but is well integrated.
One of my best investments for winter riding.
Craig