Mike Beltran is good, agreed. Cool guy, too.
Big Dan is mediocre. He's vastly improved over his performance in the late 2000s, when he was considered one of the worst refs and biggest clowns in all of MMA, and with good reason.
Still, he had a shamefully late stoppage in Jacare-Weidman that saw Jacare screaming and cursing at Dan to stop the damn fight as Weidman writhed on the floor, his eyes rolling around in his skull, and his reffing for a Michael Venom Page was shameful and suspension-worthy, with Dan taking away dominant position and a point for MVP talking shit to his opponent and then later cursing himself at Page. This was all because Dan dislikes showboating, nevermind that there is no precedent for what Dan did in the actual fucking rules.
Fun fact about Dan: He was a judge before he was a referee, and was responsible for one of the most infamous robberies in MMA history, awarding the Bas Rutten vs. Kevin Randleman fight for the heavyweight championship at UFC 20 to Rutten.