These days I only use APX 25 when I require the slowest film I can get, such as for long exposures with moving water. I rate it at 12. I love the Pan F+ because it has very fine grain and an excellent tonal scale. I typically rate it at 25 and develop in PMK.(posted 8967 days ago)It doesn't surprise me that APX 25 is finer-grained, but when I make 11x14 prints from 6x7 film, I can't tell the difference between the two.