Estregan's movies often dealt with themes of social justice, heroism, and the struggles of the common man, resonating with Filipino audiences and earning him a special place in their hearts.

: A later entry in his filmography that leaned into the explicit trends of the 1980s.

Most production companies (like Seiko Films and FPJ Productions, where Estregan worked as a co-writer) have either dissolved or lost their physical assets. The nature of these films stems from three factors:

His talent was undeniable. In 1972, he reached the pinnacle of his craft, winning the award for his performance in