Back to C permit:
How would they count the years you have been in CH? Only the years you have been working are counted or the whole stay time? Does your work permit have any influence? I have a feeling that they decide individually! I read in Halloschweiz forum the story of a PhD student who convinced them (Bern) to count his whole stay and there were others who didn't make it! His case was rejected in kanton (Basel I think) and he sent a complaint to Bern. He received a positive answer within a month.