I've actually just started testing Pan-F+ 1+50, using a mongrel testing technique:
1) Determined preliminary EI by comparing a grey card to prints of zone V negatives exposed at EI 25 to EI 100 (EI appears to be 40 when developed 7.5 minutes).
2) Determined density of zone VIII negative by comparing fb+f and zone VIII print times as discussed in [size=3][size=2]The Ansel Adams Guide : Basic Techniques of Photography - Book Two. (Density appears to be 1.25ish) and by visual analysis of zone VIII print (seems a bit too dark).[/size][/size]
This matches very closely my experience shooting with this combination over the last year or so. I may adjust my development time up a bit to raise the tone of zone VIII.
I'm using an Omega D5 condenser enlarger, so my only concern is that the density of my zone VIII seems a bit high (St. Ansel says it should be 1.15 to 1.25?) I may redo the test using another paper, since paper response biases visual analysis.