Speaking as a life long Nightmare on Elm Street Fan, and a huge fan of the BSD movie, BSD is just a better game all around. One of the games that will last the longest in my collection I bet.
Not to say that Freddy isn't kinda fun to play, but the execution failed to live up to the theme on that pin... especially the sound. Like lots of Gottlieb games to me actually.
If you were going for a "completist" horror theme pinball collection, I'd say Freddy would be a must. But otherwise, you'll have to love the theme enough to look past the issues for it to have staying power. Even if you don't like BSD the movie, the gameplay is so pure and brutal that it keeps you wanting more.