What do you define as "In the city?"
I ask because I think it's relative to each of us. I read that review about the BMW scooters being a little heavy or cumbersome around town and have heard others say that so-and-so scooter is probably to big for city use.
While still new to this thing, when I think of city, I think of my hometown of Fresno. It's got over 500,000 poeple and due to an unchecked and poorly planned explosion in growth, it's mostly suburban with boulevards that criss-cross each other, often with speeds of 40-50 mph. Most of these roads are straight and controlled by stoplights. Again, I only bring this up because I feel my 250 is absolutely the smallest I'd want to ride and feel that any of the maxi scoots would not be an issue (again, never ridden one though).
Now, when I think of the town I grew up in as a child, 14,000 people, 6 stoplights, and only two roads with more than one lane, sure a 50cc would be great because most roads had a 25 mph limit and a Maxi would likely be overkill. Of course, you'd need the Maxi scooter to go anywhere interesting. We had to travel 20 minutes on the single or double lane highway just to get to the closet movie theater, department store or any store that might actually advertise in the paper or TV.
Just some ramblings,