Hahaha, obviously you never had an issue with excessive oil from Canon before. The 1DsM3 oil issue threw so much oil around that everything was covered with oil, sometimes including your attached lens (not something you can clean yourself)! Having to send a body back in to Canon cost time and money so I think it is worth being concerned about. I don't think we should avoid having the fix done by Canon, but I am concerned about having my body come back clean until I shoot high speed and it throws over 1000 drops of oil everywhere. Given that consideration, I'll only send in my 1DX when I have the most down time. I'll also make sure my backup 1Dm4 body is clean and ready to be used full time.
You call it worried, I call it prepared.
Being prepared is good, and you are right I have never had an issue with Canon.
I guess I am lucky in that I do not send my camera in for repair, I take it in and pick it up personally, and thanks to the warnings here I will make sure I stick it in high speed mode and hold the shutter button down before I leave - just to make sure there are no issues
Like you, I am also prepared, and if Canon wants to keep it for a week or a month, it really does not bother me, though of course I would prefer it back asap. As it is, they say they need it for 3 working days, so I should be taking it in next week or the week after.