The fastest guys at my track, with the exception of one, are all really smooth on the throttle. There's a little blipping every now and then, but for the most part, it linear pulls getting on, and off the throttle. I also found that I was much more comfortable with my truggy when I made a conscious effort to make smooth, steady throttle inputs.
Think about it this way, if you're constantly on and off the throttle, your suspension has to constantly react to differnt load inputs, as well as the track conditions underneath it...there's no way to be consistently fast if you can't be consistently smooth.