Oh, I think Durham is like every other Special Prosecutor, including Mueller, Starr, Fitzgerald and Walsh. They really can't prove what they were supposed be investigating, more often than not, someone else already investigated it and found no wrongdoing, but they have an unlimited budget and the ability to ruin lives.
But all those other guys were ACTUALLY ABLE TO GET CONVICTIONS.
Let's take Lawrence Walsh. His job was to investigate Iran-Contra. Except that Reagan didn't actually any laws with Iran Contra. It was entirely in his preview to sell weapons to Iran (Actually, we sold them to the Israelis and the Israelis sold them to Iran with our blessing). He prosecuted North and Poindexter and actually got convictions. Except those convictions were thrown out because those guys had already been granted immunity hoping they'd break bad on Reagan! Then he went after Cap Weinberger who was actually AGAINST the scheme to sell the weapons to Iran.
Of course, when Walsh left with very little to show for the millions he spent, he filed a final report accusing Presidents Reagan and Bush of all sorts of wrongdoing.
So Durham got one guy to plead to changing wording on a warrant extension that would have been granted anyway. His prosecution of Sussman failed. His prosecution of the Russian Dude failed. He got nowhere near filing charges against ANYONE at the FBI.