There is quite a lot of difference regarding the two types of Predator (Predator A and Predator B).
The Predator A has been lost in theatre mainly due to i should think to it's low cruise speed and low-medium level altitude, possibly the pilots (hick) maybe flying much lower than needed also....
Predator B (Reaper) seems to enjoy a much higher cruising speed and an altitude comparible to a biz jet!
Pred A Cruise Speed - 70kts +
Pred B Cruise Speed - 220kts +
Pred A Ceiling Altitude - 25,000ft
Pred B Ceiling Altitude - 50,000ft