artusio

As far as I know is dachengdao should be a xingyiquan substyle. Whether it is effective or not in a street brawl, well ... I don't know: guess it depends 1) on what you mean by effective and 2) on your skill

Apart from the Karate Kid series, I know of "Kill or Be Killed" (south-african film which features both fighting and kata) and a documentary film about a kyokushin karate tournament, "Dragon", if I'm not mistaken. Both were shot in the late 70's. You can find more on "Kill or Be Killed" in this forum.

you can find reviews on rotten tomatoes or yahoo movies, for instance, anyway you'll find it to be very underestimated. In my opinion the best martial arts film ever shot ! The idea of a nazi general taking refuge in Namibia and puttin'up a karate olympia is a manifestation of pure nonsense genius (a very Avenger-like plot, if you see what I mean). Suondtrack is very good too !