Just my opinion, and take it how you wish.  I am far from an expert flyer.  far from the perfect plane setup, but never once, and I mean never have i had a problem with signal.  my antennas don't always point 90 degrees from each other, batteries aren't fully charged, and again never a problem.  I have seen a lot of planes go down with a certain brand of radio, wether it be pilot error, or equipment, who knows.  It all goes back to.. "you get what you pay for"