Despite the seeming sophistication of weighted and exponential moving averages, nearly every test we've seen or done ourselves has shown the simple moving average to be superior to the others in terms of trading results.
Our own research indicates that weighting the data to emphasize recent events makes the indicator overly sensitive, thereby negating the original purpose of the moving average: to smooth market action. Weighted and exponential moving averages tend to generate more trades in tight, trading range markets than simple moving averages
This tends to confirm a theory we have long held: Any entry method that is the result of an abstruse calculation is probably more trouble than it's worth.
--Charles Le Beau & David W. Lucas, from Computer Analysis of the Futures Market (1992, Business One Irwin, Homewood, IL).