I've used Pan F+ for years in 120. I live in LA so we have plenty of sun for me to rate it at 25 and still get shutter speeds of 125 and higher. Yes, it does take some time to get used to, but once you do, it's a great film. I use Rodinal 1+100 for 18 minutes with regular agitation. I've also kept exposed rolls of Pan F+ in my freezer for over a year and they came out fine when developed.