In the past few months I have flown KLM's WBC on all wide body aircraft, 747's, MD-11's, and 767's. As far as the product goes, its no Cathay Pacific or British Airways, but is still very good product. I tend to fly KL over some of the other European airlines simply because of WBC and AMS. The crew have always been fantastic, I cannot say enough good things about them. As far as the food goes, I have had some excellent food, but at times it has been a let down too. It has never been inedible though and always seems to be filling.
Here are a couple trip reports for you. I hope this gives you an idea about KLM's WBC.
http://www.flyertalk.com/forum/Forum81/HTML/003492.html
http://www.flyertalk.com/forum/Forum81/HTML/003530.html
Hope these reports provide you with the information you need.