American Express Membership Rewards - AMEX Gold x AMEX Platinum

I am AMEX Gold and pay US$ 195 fee for me and 1 additional card plus Membership Rewards annual costs.
I just received an invitation to the AMEX Platinum at US$ 595 annual for up to 4 cards (1 basic + 3 additional).
Is it worth ? Are there many advantages with the Platinum AMEX ?

As discussed many times here, the Platinum card benefits depends on the country where it is issued.

As Platinum is still the premium Amex card in Brazil (no Centurion card available), the services and benefits could be worth it (if you fly Continental from Brazil to the US or Canada in BusinessFirst with someone !).

The Priority Pass card seems not to be offered as a benefit, so I think that the annual fee is too high .

Have a look at www.americanexpress.com.br (http://www.americanexpress.com.br) to compare the benefits of Gold and Platinum in Brazil
and http://www10.americanexpress.com/sif/cda/page/0,1641,16632,00.asp for the Plat benefits.