Personally I love raiding as a strategy and Ive used it. But I tend to see it used more as a tactic. Its not the path by which a person tries to win the game. But its useful to keep in the toolbox.
Especially if you come up against a full strategy which seems completely planned out and unwaverable. Switching from marching armies to raiding can scramble the other guys plans. Forcing the purchase of PD instead of units can mess with carefully laid out timelines. Scatter his massive army into smaller ones trying to find you. And if you are lucky you might even run into someone that just doesnt change tracks well. But even then it tends to be the key to bringing a nations exapnsion to a halt but some other nation tends to be the one to take it out.
As much as I love using stealth in many different tactics, Id have to admit that its not seen much as a key component to a winning strategy.