KFm-4 vs KFm-2 HD

This video shows two of my FPV49 wings that uses different KFm airfoils. The videos was shot within a few minutes on the same day so weather conditions was similar for both flights. ( here you can see some more clips from the KFm-3 wing: http://youtu.be/_jVoYRM-uOw ) The layout of the wings is pretty much identical, the main difference is that the KFm-4 wing is heavier than the KFm-2. When flying the KFm-4 feels more like its on rails. It wants to go forward. While the KFm-2 get tossed around a lot more. This is just my opinion and may or may not not be true for other types of planes, builds or pilots. Music by CMA: www.youtube.com/user/Epzonix