Well I do not do Wing Chun but I've been doing a Martial Arts called VOVINAM for about 10 years, once a week,
2 hour sessions and I think it is enough. This has got some unique moves which you can see in the movie FlashPoint (Donnie Yen) like flying head scissors.
PS: These flying head scissors should not be attempted at home with no supervision as it is quite dangerous and obviously not that easy. This is because I've only about a year ago been allowed to do them. EACH STRIPE ON EACH BELT TAKES ONE YEAR AT LEAST