Once I had to shut off my Fuji 64 with the choke after the kill switch ground wire failed. Since the engine is inverted in my plane, the plug was too wet to fire when I tried to start it after repairing the wire. One downside to choke to kill that I've seen in weedeaters and other small two strokes is varnish build up when stored over a long time. It usually doesn't hurt anything, but the bearings and piston can become a little sticky if overwintered with a great deal of fuel in the crankcase. The rev and choke to kill might cause premature failure of the metering diaphragm in some carbs, due to sudden high vacuum conditions in the carb throat.
I prefer to just use the kill switch. For me its easier, since mine has a manual choke which puts my hand very close to a big prop. I also figure I'll get a little more life from the plug before fouling.