One thing I noticed about my Eflite models is that they are subject to alot of ground effect when hovered too close to the ground. When I was training with my training gear on I noticed the ground effect went away when I decided to go "no guts, no glory" one day and immediately shot it up about chest hight upon spool up. Hovered darn near rock steady! In my shock I panicked, zeroed the throttle and thanked the stars that the training gear absorbed the hard landing
Not sure if this same effect happens with the T-Rex's though.
Added note: CX2 is prone to "ceiling? effect". LOL