i want to know the power of the kites i would be happy to cooperate ,and to get your impression on the kites:
ar5 is 13.5 is abit weaker then the arx but move faster.
f-1 15.1 same pawer and even weeker then the 13.5 ar5 but much faster
the north 16 much stronger then the 13.5 arx (esteemate as 14.5-15 arx)but fast as the 13.5 arx (and very accurate).

Perhaps this helps:

http://groups.yahoo.com/group/kitesurf/files/Mach 1 Wind Range Comparative Chart.pdf