This article from the Met gives insights into singing Verdi from some of the best Verdi singers today.
These little paragraphs are full of interesting perspectives. Marcello Giordani is perhaps the most interesting because he talks about the color of the tone that must be maintained.
I already wrote my essay on singing Verdi here. There is no conflict with anything the singers say. It takes a minimum amount of force and stamina to sing major roles in Verdi operas. The point I was trying to make in comparing Adrianne Pieczonka and Karen Slack is that the rest is about music, not voice.