[sub]All interesting but if the testing has been thorough and successful then they already know full well that 2f will be fine once it reaches its final position. Its then simply a matter of swapping from the other sats to 2f - possibly even overnight if they want! If the testing was all OK they can be virtully certain it will be OK once swapped! Even then it could leave a pretty wide margin until the Chistmas peak - and even if it does not work, the old sats woud still be there for a while and could be used whilst problems are sorted out. I don't think there is any reason at all to delay swapping sats as soon as they want.[/sub]