Not only have I played some of them, I playtested some of them. I thought I'd get playtest credits in Herocard Nightmare, but apparently not. That's ok, got other swag instead.
I've played: Rise of the Shogun and one of its expansion, (not sure which), Nightmare (my favorite), and Orc Wars. Also played Martinis & Men and Wealth of Nations, but those don't use the Hero Card mechanic.
You could think of Hero card games as 2 games in one. One uses the "hero" cards to duel the other players. You have a hand of cards you exhaust and replenish hoping to beat the cards your opponent plays. These then are reflected on your character on the game board.
OrcWars is probably the most extensively tested, at least by one playtest coordinator and his subjects, (hey Monte!), but I never won a game, and my general feeling/rule about games is I don't like them if I never win them. Basically you play 1 of 3 heroes and 1 player controls the orcs. Various scenarios are outlined in the rules, such as "Save the sheep" (ok, I don't know if that's the name, but it is the objective). You have to get as many sheep off the board while the orc essentially wants to eat them.
Hero card Nightmare is kinda like Clue. You are all stuck in a nightmare and essentially the only way out is to get somebody else killed off. The board morphs during play depending on who you want to protect or attack. You can move your player or the killer around.
