For a semi newbie,I can fly a cp+ back and forth and hover ok. Looking at a trex 450sa, but having a hard time on servos. I am thinking about the jr servo pack (comes with 3 ds 285 and 1 ds3400g) for $159.00 , any thoughts on these ? or are ther better buys out there? I really don't much between one servo and another. is a $30 dollar servo that much better than a $13 dollar servo.