GROCHFAN is quite correct --all the trainers, while sharing many basic similar charateristics are not exactly the same and have different handling somewhat.some are identical in different colors but just because they share the same type of airfoil does not mean they fly identical. one arf out there has vastly better ground handling in wind than the others, some are smoother flying. the amount of dihedral the manufacturer chooses to design in has a big effect on flying handling.but overall it is only small differences for the most part. changing airfoils will alter the flight charateristics depending on how drastic the change is and how experienced the flyer is in noticing such changes. semi-symetric does not handle (everything else being equal) quite the same as phillips entry or true flat bottom. Eagle II does not handle quite like a Kadet. percentage of airfoil thickness has a very marked effect upon flying.our airfoils are small so differences are too but they are there. witness the old Goldberg skylark(with semi symetric) flew &handled different than the newer version with full symetric as experienced by a club member who was sent the wrong wing for a repair.other examples could be cited.