Although I totally agree with the decline in service since the start up of FB, and the considerable and often questionable service ethics of KLM in general I have never had a problem getting my seat assignment.

I too am Gold and fly at least five times a year to the US and back and have never not got my "select seat". Sometimes I do not get the row I want, but hey....I do not mind as long as I get what I want.

I book my tickets on line and then call the e-service desk and then request my seat.