I've had to go through London with mine in the rush hour a few times, generally going to or from an airport. It's useful for backing into a corner and using as a rest when it's full of clothes. That also makes it hard for people to nick stuff out of it (although anything valuable in mine is buried deep).
I don't like those wheeled cases either, and reckon they look ridiculous. A decent briefcase or a flight bag carried by the handle is much more dignified. It also makes it a lot easier to sling it into a luggage rack or under a seat. They now have shopping baskets that trail behind you as well, which are equally silly, although the proper kind are a pain to carry. As for the big ones, I sometimes use my trunk as a mobile seat (useful for that). However, they are quite good at giving you shoulder pains. The ideal solution would be a sledging harness, possibly meaning you could tow three or four.