All those years of D&D and now I can't believe I ever wanted my fighters in plate.

I disagree. Imagine what it would look like if you had someone in that plate mail facing off against a peasant with a pitchfork. They look like they are demonstrating advanced techniques specifically designed for armored combat. Everything else is going to look like the first few seconds when he just stands there while the other guy took a full body swing at him, right before he swings back at you and cuts you in half.

A Sherman might not look so tough compared to a Panzer, but to everything not inside a tank, it will still make you shit your pants.

Those are far more mobile than I expected.

Agreed, I was surprised at how they were able to get up off the ground. I always thought it would be like a turtle flipped onto its back.

The idea that an armored knight was helpless if he fell is a common myth, but no more than that. There might have been a few specialized cases of jousting armor that were actually that heavy, but nobody would go armored if all it took to beat them was to knock them over.

and any time hollywood showed off people in armor, they always made people look slow and cumbersome, which feeds into the idea that its a lot tougher to fight in armor like that.