Il Divo is massively overrated. We can thank Oprah for them. I actually caught that episode...Big mistake.
Whether as a group or individually, they don't bring anything to the table. I don't really consider them musicians. They don't compose or arrange anything that they sing, and they don't communicate the things they are given to see.
From a purely vocal standpoint, none of them bring anything unique to music. They don't even have a true genre. They are NOT opera singers or in the classical genre. "Popera" does not count because classical singers will not claim them and pop musicians don't accept them.
Not a single one has an identifiable voice. Whether it's pop music or classical music, a vocalist needs a distinctive sound. When Justin Timberlake is on the radio, you know it's him. When Luciano Pavarotti sings, you know it's him. Il Divo just sounds like four generic and mediocre lyric baritones getting together trying to outsing each other.