There have been many succcesful pulse jet Rc airplanes in the past and presently although not as widely used as in the still active controlline speed jet class.
Chief dissadvantage of course is lack of throttling fairly low thrust compared to a true turbine and the almost imperitve need to use a fully exposed engine for cooling to prevent valve failure.
Operationally The aircraft must be launched in seconds agine to avoid valve failure.
Here is a pretty cool fairly recent twin:
http://www.youtube.com/watch?v=1e-Ar7gb4tQ