Mir is worth the hype. Every fight he looks stronger, leaner, and faster.
In his first fight with Lesnar I think it was his intention to just allow the takedown versus trying to compete with such an accomplished wrestler. With his comfort level from fighting from his back I think he was willing to take what some view as a disadvantage position.
In the second fight I think he was trying to avoid Lesnar's wrestling again with his dramatically improved striking. He was doing very well until he got over-excited and threw the knee. Once Lesnar got the game into a grappling match, Mir couldn't compete with his strength. Mir openly admits this and has worked to be more physically competitive with Lesnar.
He's a huge guy, elite grappler, improving his gameplans, and he's knocking people on their ass. If it was anyone but Mir people would be bear-hugging his nuts.