There would be 2 major differences.
1) Differences in search -- it would provide smoother search.
2) Differences in data input - it would be much easier to enter resumes / job descriptions.
Now let's consider these differences in more details:
1) Differences in search
1.1. Every keyword would have weight. Compare it with current situation when keywords are just yes/no criteria in a filter.
1.2. Weight of every keyword (or phrase) would be evaluated automatically, based on user preferences (what resume does user like/dislike).
1.3. User will see all position sorted by user's preferences.
1.4. Every time when user reads the description - user would evaluate it (very short - "I don't like it" / "so-so" / "I like it". This evaluation will be taken into account and applied to sort the rest of the positions.
2) Differences in data input.
2.1. Data entry would be highly automated. Instead of filling many fields into database user will just cut&paste the resume / JobDescription. Or even email it to database. The system will parse the resume/JobDescription and insert it into database in searchable format.
2.2. JobDescription would be automatically rated according to "search users" preferences.
E.g.: if there are 1000 search users, then new resume/JobDescription would get 1000 ratings.