Too many people! Crowds and crowds and crowds of people always walking across the bridge, blocking…read morethe sidewalks, jamming the flow of traffic, and making it nearly impossible to make transfers in a timely manner, particularly on the weekends.
I like to avoid this route, but it's unavoidable when transferring between the U-Bahn and S-Bahn. All other times, however, I prefer the other side of the bridge, just because there are less people.
Also, the view out over the train tracks is kind of desolate and sad, but sometimes you can catch the perfect sunset, and that makes it worthwhile.