I agree with everything Dominik said. I think the hardest part in applying wc is maintaining bridge contact vs an explosive striker (e.g. a boxer). Your footwork is almost always going to be too slow to do this when responding to a snappy jab. wc is a product of it's environment. A lot of kung fu and karate leave the striking hand out, which enables the establishment of bridge contact.
like aikido, wc's most useful application (in my opinion) is for women's self-defence. guys seeking to dominate women tend to employ tactics which they wouldn't even consider vs someone with comparable strength; i.e. grabbing the wrist or some item of clothing. this creates the openings wc needs. vs a bloke - men generally strike or get a more comprehensive grip.
if you do find yourself in trapping range, then wc is by far the best ma to know (for that situation). but to have that level of usefullness takes a long time (bill cheung says at least 7yrs). the filipino martial arts (fma) are much more applicable to the western environment.
i read somewhere that the transformation western boxing underwent since the beginning of the century is due in large part to US sailors getting owned by much smaller filipinos (when looking for trouble on shore leave). the body mechanics are identical (turning the hips from the balls of the feet). the whole range of bobs, weaves etc, etc, are all accounted for in the fma.
eskrima, for instance, teaches the use of the stick, then the knife and then the hands. the hands are last, and easiest, because the body mechanics and angles are all the same. thus, eskrimadors don't seek the bridge/trap (like wing chun has to) they simply take it if available.
most of the trapping used in fma is initiated when facing the stick of knife. the reason being that people tend to commit muich more to a strike from a weapon then they do when striking with the hand.
i believe wc should not be a person's primary martial art, unless they are physically weak and only seek self-defence. i'm planning on returning to wc when i'm older, as it's usefulness will increase the frailer i look.