Titan rushing can be a good strategy, but its not always the best thing to do. If your opponent is building up a fleet and you're saving for a titan, guess who loses if he attacks before your titan is done? And getting a superior economy can be just as important as getting the titan first, as you can quickly close the gap with someone who build a titan with a bigger fleet to boost.
The person who gets the titan first does have an important advantage as they will probably have the highest level titan, but its not a game ending scenario as it was in the early beta. Really when to build and use certain ships and strategy is the main thing this game is about, and its something that only really improves with practice as you master the game.