the thing is, these m.a. crossovers work maybe as well as any other single indicator. maybe a bit better according to my work. but, if you can cobble together a couple of good indicators - or more - you will likely beat what these m.a. crossovers can do.
for myself, i have done extensive testing for a couple years now. i have not found any one indicator that is better than 50/50. so, adding a couple together is not improving anything. so, i just do m.a.'s, close my eyes, a forget about thinking i know where things are going.
i get a cross, i go long. either i'm stopped out, i take what i think are good profits, or the m.a. crosses back the other way and i have to close out and take the opposite position.
i also compliment the m'a' crossovers with trades based on les's data, which kind of take the opposite view of m.a.'s. it would seem to be the perfect compliment to a crossover system.
i'm currently long and losing money based on les's data, but with the m.a.'s i never lose more than a quarter on SMH.