While class distinctions are still very important in the UK (most English people can tell which class you’re from, and where you were born/brought up, almost before you’ve finished a sentence, its that ingrained), after WWII the rise of the middle class has lead to less emphsis on it, and more on material wealth.
for instance, most people in London and the surrounding area speak, in what my mum used to call “Estuarine English”, ie sort of a watered down Cockney, so its difficult to tell exactly what class younger people belong to by thier speach. I know, I’m one of them – despite growing up in the affluent middle class suburb of Putney, years of living in South East London has given me the sort of accent you’d expect from an extra on “Eastenders”.
You’re right in the fact that the very rich tend to be much more understated, but the stuff they have tends to be of better quality. And people tend to hang on to houses – especially in the posher areas of London – and pass them on to thier kids. This is “old” money, so they don’t feel the need to show it off.
Having said that, Margaret Thatcher lives in a newish Gated Community in South London, but they certainly don’t build McMansions in London, simply because there’s not the land to do it.
Of course, the younger generations do like a bit of Bling!, but on the whole people are wary of too much showing off. Despite being class-ridden, there’s still a strong undercurrent of Soci-alism in the UK that finds ostentatious displays of wealth tacky and in-your-face. But, then again, there’s David and Victoria Beckham, so who knows…
But, I’m sure its much the same in France, too, n’est ce pas?