having toured with 6 and 7 speeds, having 9 or 10 is nice just cuz the jumps between gears is much easier for those specific headwind/inclines where one gear is a bit high, the other a bit low , sort of thing.
Don't know if you have other bikes but for other than an expeditiony type trip, I would absolutely go 10 speed next time (8,9 is what I ride now).