It is a very effective way to fish.Many people actually tie their flies on jig hooks.As far as I know, this is perfectly legal.
I prefer to fish the traditional swing with a sinktip but will sometimes use the "jigfly" method. Throwing heavy flies with a dry line is just not that much fun for me.(especially if you hit yourself in the back of the head with the fly).
My only gripe about indicator fishermen is they tend stand in one spot and not move through the holes in a considerate manner.Remember a few years ago when they closed down the area around Deer Creek? Everybody knew the fish were there and just pounded the crap out of the hole with their jigs until Kraemer shut it down.