It has worked for me.

But everytime I have used it I have wanted to upgrade two sectors. It has only upgraded one sector and then the second at a later date. It then does not then discount the savings as two sectors combined are normally less miles than two sectors individually.

A call to EK has always sorted it out and they have put it through as a combined sector upgrade .

I find EK staff in the US are more helpful than EK in DXB when calling to do this.