How good is Dirk Nowitzki to others?

I live in Dallas so everyone's opinion of Dirk Nowitzki is very biased as he is the hero and leader of the Mavs. My friends and I all greatly respect great players around the league such as Wade, Bryant, Garnett, James, etc. and every time the Mavs go against one of their teams, I'm like ugh not Lebron. My question is how do you other NBA fans around the nation feel about Dirk Nowitzki in terms of his game and how much you dread when your team plays him.