Well, lets set aside that I live in Palm Beach County, where most of the customers at the local Bentley dealership(s), go and purchase their automobiles whilst wearing a polo shirt, shorts and some type of loafer (many times sock less). With the heat reaching near a scorching 90 Fahrenheit degrees for weeks at a time in the summer, not to mention the enormous amount of humidity, wearing heavier D&G, Dior Homme, Fendi, Gucci, Prada, with high quality Italian jeans and especially long sleeve shirts can easily become a quick way to face massive dehydration, which when placed in the face of fashion, wins every time. As well, lets wet aside the larger-than-average per capita income in the PB County. When looking at the average American, then yes the staple of khakis and GAP t-shirts seem to dominate the landscape, but if you compare London (as we have established, a very expensive city) to say Manhattan (similarly expensive), then the style and fashion of dress becomes a lot more similar and you will see D&G, Dior Homme, Fendi, Gucci, and Prada on the street. There are some American items that made their way across Europe, such as the removable collar and the button-down shirt collar. Plus Brooks Brothers pioneered the concept of RTW suits; but Europe does not produce any RTW items, do they?
I would think that it is better to appear less fashionable and to appear more classic (stylish), to appear that your clothes fit perfectly (well, almost perfectly; nothing is perfect after all is it?). If you walk in one of the aforementioned cities, you are more likely to see people wearing expensive designer wears than to see someone wearing a clothing item that properly fits. Jon.