This movie has certainly been trumped in terms of special effects and overall production value, but in terms of the writing, the comedic performances, and the general quality of the flick, this movie is light years ahead of the vast majority of similarly aimed recent comedies.
This movie is timeless; it's deficiencies, in terms of effects, makes it that much more charming/quaint.
What's really funny is the fact that this movie was the most commercially successful comedy of the 80's (in terms of box office take).