I've only seen one in person, it seemed rather loud, but it was a worn out engine on makeshift track, it is now undergoing complete rebuild. I was just watching a Cass video of a big weekend with everything steaming. The Climax was loud, almost drowning out its own steam exhaust. It was like the gears were in need of lubrication. Really gave the impression of being a bucket of bolts, not a newly restored engine. Is this normal or did the video cam microphone just get locked in on that frequency?