Guild Wars 2

Besides having better rewards at certain tiers e.g. (1-5), (6-10)… and bosses getting agony damage from level 10 onwards, what is the difference between, say, Fractal difficulty 7 and Fractal difficulty 9?

http://wiki.guildwars2.com/wiki/Fractals_of_the_Mists

i don’t think there is one. from what i’ve noticed, everything between tiers (10-19) are the same.

From guildies talking, apparently more and different monsters spawn in various encounters, as you reach higher scales (20+, 30+, 40+ etc.)

10-19 are not the same in my experiences, there is a little difference in difficulty there.