The ones who are doing Actual Play podcasts and YouTube shows? They're pros in the sense that they're getting paid to DM.
All of them except maybe the "three hour long fight" one seem to be pretty standard for Actual Plays that I've listened to or watched. But that's because what makes for a fun listening experience isn't the same thing as what makes for a good gameplay experience. Good APs tend to be more like improvised radio plays that use the game as a structure for improvising off of, which is not the same thing as what makes a good game IME.
(Who is running three hour combats in an AP by the way? That sounds like it would be immensely boring to listen to or watch.)