A15 is an excellent kite and the jackomixer works very well with it. I am not sure why someone would say the Jackomixer only works with the Genesis? Bar pressure is high with the Jackomixer on the Genesis but not on the A15.
There is a new very good mod for the Genesis http://www.lesfoilz.com/phpBB3/viewtopic.php?f=4&t=5175 . Apparently Pansh will be releasing it soon on an updated Genesis.