I went to a baseball double header in St Louis in 94 versus the Atlanta Braves, afternoon game was tremendous, the night game was a fucking horrific experience. I went with my sister in law to the night game, she was followed into the bathroom, leary comments, booze thrown at her and the atmosphere was probably the worst I've been around at a sports venue.
The difference I've seen at US sporting events is that it's individuals rather than a collective that mar the experience, at Metlife there was sporadic fighting among Jets and Browns fans, at TD garden a guy wanted to fight a lassie because she was late getting to her seat and he couldn't see past her for 10 seconds, at Gillette there were Lions fans trying it on with our group all through the 2nd half. This idea that there's no crowd trouble is a myth, it's just less obvious. Don't get me wrong I've had great times at all the events I've been to bar Busch stadium at night which was really ugly, the difference at US events is no segregation as such and everyone gets the same treatment through the turnstyles and no over zealous stewarding of groups of away fans.