This episode is not unlike every other pilot for a Star Trek, or even a Sci-Fi Show. It introduces the main character, in this case the Enterprise Crew, and place them in a dangerous situation immediately, namely the task of bringing Klaang to the Klingon Empire, and it introduces an enemy that'll recur throughout the series, the Suliban and the Temporal Cold War.
Most people have an adverse dislike for the show immediately because it "differs" from the other Star Trek series. Most people just dislike the Captain, which is very similar to the Picard and Kirk 'esque styles of personality which became so well liked in both previous series', however others contend that this series alone was an unnecessary gap filler.
If you take Enterprise as just another Sci-Fi show and not as a Star Trek Prequel then it becomes an enjoyable series worth the watch, and this is the first in a line of episodes which show that Human Ingenuity and integrity can overcome anything in a hostile environment.
Well worth watching.