HMM, i own a ozone viper 3 .i have flown for 6 years and still have the wing. very good glide rate. i use the wing more for acro. i also have the ozone viper 4 wing another very good wing. more agile then my viper 3 wing. probably because the viper 4 has 2d risers. i also use for acro flying. and general flying.the unsheathed lines. can get tangled easy. hence why you need to be a expert to untangle the lines... can be problematic. as far as iam conerned the vipers are for free style flying. and not xc flying. the viper 5. ozone say this and say that. and ill take that with a pinch of salt... the viper wings are action wings. full stop.