I'm citing an economist's work here, but I think it's valid.

In "Kicking Away the Ladder" Ha-Joon Chang discusses how Western European nations did exactly what you talked about during the 18th Century, which helped enormously in their development and really spurred it along.

However, the most striking example is the United States, which had very heavy tariffs throughout the 19th Century and defied Adam Smith's advice for them to focus on their economic specialties. The United States instead imposed tariffs and focused on developing an industrial base. It pretty objectively worked, as Niall Ferguson discusses in "Empire" (I always dislike citing it due to its Imperialist bias and my ambivalence about Ferguson, but in this case it's absolutely correct) by the late 19th century America had surpassed Britain, France, and Germany in industrial production combined.

So yes, it's safe to say that Import Substitution has been very successful economically, since it basically resulted in the industrialization of Western Europe and America, leading to their ascendence as Imperial, economic, and military powers.