I have the book "A Gown for Diana" written by the Emanuels about the entire process. Diana's gown belongs to the time she lived in and at that time, it was something to behold. I still love it and always will.
I feel the same. Love it or hate it (and I love it) you see that dress and it transports you back to a time when we all believed fairy tales could come true. That was a Princess dress if there ever was one.
That said, Kate will wear something much more elegant and understated. It's just who she is.