Simple fact is if you **** up as a SL you're generally forgiven easier, especially if you accept plans your squad members come up with - whereas when you're a pilot, you have a million things to think about, to worry about, and PR is very unforgiving, both as a game and a community, towards pilots, if you lose concentration for a moment while flying it's very easy to lose control of the aircraft, losing you team up to 13 tickets and gaining a hell of alot of abuse and sometimes even a kick from a server. Mumble makes it easier - and can take away some of the abuse (You can keep the guys in the back informed of your situation, people tend to be calmer when their heli's gone down after the Pilot is telling them exactly what's happening, i.e telling them he's taking fire, or is losing control, or the rotors are out etc.).
Just my 60p









