I enjoyed it a lot more than Crash Course. It's short but still a lot of fun, especially in Versus. Versus Realism is also a great addition that cleans up a lot of my issues with Versus play. There are some stealth updates with the DLC that should make the game a little more balanced and fun. Some of the weekly mutators should be fun to play as well. All in all a good free update for regular L4D2 players, though probably not that fun for the people who wanted something substantial to play through once.
Kind of an aside, but some of you should really play it more than once and maybe try some different modes. It's not really fair to play through the 45 min campaign once and judge it, especially since you get to hear different lines from the survivors with multiple plays.