Hi Michael:
Sorry for the late reply — I was out of town for a couple of weeks with no email access.
I suppose my boxer's-blast activity falls into the "sometimes" level of frequency. In JKD class, I tend to use it as a "rally" when I have my opponent back-pedalling and know that I can charge forward with little resistance. Against JKDU guys, I never get in more than four or five punches before they cover/shoot/etc. Against non-JKDU guys, I'll use it Royce style as an entry from outside the measure. I actually ran an undefeated amateur boxer across a room and into a wall with it last summer (it only worked once though; he had a nice counter waiting for me the second time I tried it
). I've always thought of the Wing Chun blast as more of an unbalancing tool than a destructive, offensive technique — it charges down the opponent's centerline and, though it doen't do a whole lot of damage (for me, at least), it gets the guy way back on his heels and sets him up for a throw/elbow/etc.
Take care and train hard,
Jim
P.S.: Michael, when are you coming to visit us again in sunny Hawaii?