I am fairly happy with the way KLM credits their miles. Generally my Friday afternoon flights are in by Wednesday and the Monday morning ones by Thursday or Friday...

I have also found that on the rare occation that the miles are not credited it is quite painless to claim them online. Only minor issue is that one has to wait four weeks, and one has to calculate (or guess) the last digit of the e-ticket number.

On the downside... I became a member of KLM Plus this spring just after KLM removed Silver Elite access to the lounges, and as they promised to give the 10K miles back when I became Gold Elite it was a quite simple choice to become a member... But did the miles come back automatically when I became Gold? Or when I became Platinum? I think not... only after a few e-mails and a phone call to the helpdesk did they show up (a month later).