I will quickly attempt to compare this course to the Barron's version of FSI Spanish. Both courses seem to have enhanced sound quality. Although Barrons doesn't mention it, but from listening to the Barron's' CDs it is apparent that Baron's' has enhanced the sound quality of their FSI lessons which were also originally recorded about 50 years ago.
Both courses also use native Speakers which is a big plus.
Baron's' calls its teaching method the Guided Imitation method. The Guided Imitation method is built upon two premises. One is that one of the most effective models to learning Spanish requires the student to study a small body of material until the material is thoroughly mastered. And the second is that language mastery depends on effectively manipulating the sounds, sequences, and patterns of a language until the learner sounds authentic. In Baron's', each Unit in the course starts with a basic dialog that's a re-creation of a real situation that the student is likely to encounter in "Surlandia." Surlandia is a mythical country in Latin America.
In FSI Programmatic Spanish a typical unit covers a cycle of work that requires about 3 to 5 hours of study for the average to above-average learner. The learning that takes place during a typical unit is sequenced as follows...