The new Star Trek film was definitely good, but in my opinion it was geared to the new generation comic-book and superhero movie fans, intended to build a new fan base. The acting was superb- Quinto was a good choice for Spock, and Pine definitely pulled off that cocky, smart scrapper Jim Kirk. Pegg was entertaining as Scotty, as well. But to call this movie a "Prequel" is definitely a mistake. It is better described as a "re-imagining" of the whole Star Trek story, from the time period of a few years before The Original Series onwards.
The way the story was changed was done in a way not new to Star Trek universe, but I am hesitant to describe it further for fear of spoiling it.
In closing, if you've never been a fan of Star Trek, go see it, it's good. If you're a die-hard Trekkie/Trekker, go see it, but definitely keep an open mind.