The following info is for central Europe- it is not relevant out side radar coverage and under procedural (oceanic) control.
Over most of Europe it will make no difference whether you turn or not. 80% or ac will on directs or if not you turn into another airway. Follow the company book to cover your ass but be aware turning will not make a scrap of difference in reality
If it is real bad just put 7700 in the box and do what you have to do. we will quickly work it out
If not so bad 7700 and a mayday call- we will clear the way for you- but you have to give us the chance.
Also you must consider that once you descend you can be entering another FIR. We have to call them and tell them- they will see you coming if the 7700 is on. If you don't have 7700- the first they might know about you if the short term conflict alarm with their traffic.
Feel free to PM if you want any more info
