Haven't played Heavy Rain. Fahrenheit offers some nice ideas, but with horrible execution. It's not just a matter of "accepting action in your adventure", it's the fact that, as the video abundantly demonstrates, there are just some incredibly retarded and intrusive QTEs. Another memorable one is when you're getting exposure in the form of a séance, and this is accompanied by a similar QTE, but at a leisurely pace. Totally pointless, not challenging, except for the fact that it prevents you from paying attention to what's going on. Indeed, in all the action sequences, I can hardly see all the Matrix stuff that Lucas is doing, because I'm only looking at which buttons I need to push. I can also hardly understand what's fun about alternately mashing left and right.
I played the PC version of Fahrenheit, but it still uses rather typical console-style third-person controls. Not good when you're struggling to conceal a murder, like in the beginning of the game. I do like that kind of thing, though. The whole "There's a dead body in this room and someone is coming" thing is not as original as I once thought it was (Fahrenheit received a bit of preview hype in the magazine that I read at the time), but it's still cool. I liked how you sometimes need to act quickly in both dialogues and actions. The descending sanity was also nice, although I'm not sure if it really affected anything unless you really fucked up (it's been a while though, so correct me if I'm wrong).
Unfortunately, even if you get through the mother of all annoying QTEs, the story just goes full retard with the whole Matrix ripoff and the hobo resistance movement. They had mysterious ritual murders, Mayan legend and the whole background of the world slowly freezing over (another cool idea on paper), and they managed to fuck it up in the end. Very disappointing.