The Movie: A Star Trek staple, a Warp Drive is a faster-than-light (FTL) propulsion method, designed to overcome the enormous distances of space. The Enterprise uses the Warp Drive to escape from Admiral Marcus' clutches, only to discover that Marcus' ship is gaining on them. Marcus shoots them down, bringing the Enterprise to a sudden halt.
Real Life: Faster-than-light travel is a science fiction staple worth suspending our disbelief over. But faster-than-faster-than-light speed? Come on, that's stretching the theory of relativity a little too far. How can you gain on a ship that's already traveling faster than the speed of light? Also, a sudden stop from that imaginary FTL speed would do more than jostle the Enterprise's crew around a little. G-forces do not mess around, and the crew would be pulverized over such a jolt. And who could think to do that to Chris Pine's lovely face?