I've now had the game for 2 days...
Once I realized the aim will follow the guy you are shooting, without user (me) interference, it got a little easier...but I am the SLOWEST knife puller ever....and a miserable pilot....
PSN: TheGodofWine (Warhawk / R2 / MotorStorm PR)
AND
PSN: Skigazzi (for KZ2 and future games)