The rating of "5 Scars" denotes a film which has been realized to its absolute full potential. A 5-scar film is, for all intents and purposes, perfect. That is, given the genre and the intentions of the filmmaker, the film could not have been improved in any significant way. Only a handful of films receive a 5 Star rating and represent less than 1% of horror films released in the 80's. An absolute must see film.
4 1/2 Scars
The rating of "4.5 Scars" denotes a film which is, generally speaking, a masterpiece of 80's horror, but with one (or a few) minor faults which prevents it from achieving a perfect score. Often times a 4.5 Scar-rated film could reach 5 Scar status given that the viewer is in the right frame of mind for the particular film in question. A 4.5 Scar film is still designated as an obligatory "must see" film for any horror enthusiast.
The rating of "4 Scars" denotes a film which is, in a word, excellent. The rating of 4 Scars isn't entirely rare, but 4-Scar films aren't plentiful, either. Generally, films which achieve 4-Scar ratings are highly enjoyable, very well done, and represent some of the better films of their respective sub-genre. 4-Scar films come highly recommended, but are not necessarily must see films.
3 1/2 Scars
The rating of "3.5 Scars" denotes a film which is not entirely noteworthy, but still quite good. 3.5-Scar films are quite common and represent films that might be considered above average. If a viewer is particularly fond of a sub-genre and a film within that sub-genre receives a 3.5-Scar rating, the film is highly recommended. Otherwise, a 3.5-Scar film comes with a subtle recommendation.